Lingua:...:Inflect(3)
okay bestie, this is Lingua::EN::Inflect(3) — the title/manual name — from the User Contributed Perl Documentation set. The header literally reads Lingua:...:Inflect(3) / User Contributed Perl Documentation / Lingua:...:Inflect(3), and we're folding it in right here instead of copy-pasting the raw line. 💅
✨ NAME ✨
Lingua::EN::Inflect— Convert singular to plural. Select"a"or"an".
💖 VERSION 💖
This document describes version 1.905 of Lingua::EN::Inflect.
🦋 SYNOPSIS 🦋
okay so here's the whole vibe — every snippet below is exactly how you use it, bestie. no cap, this is the group chat of inflection examples:
use Lingua::EN::Inflect qw ( PL PL_N PL_V PL_ADJ NO NUM
PL_eq PL_N_eq PL_V_eq PL_ADJ_eq
A AN
PART_PRES
ORD NUMWORDS
WORDLIST
inflect classical
def_noun def_verb def_adj def_a def_an );
# UNCONDITIONALLY FORM THE PLURAL
print "The plural of ", $word, " is ", PL($word), "\n";
# CONDITIONALLY FORM THE PLURAL
print "I saw $cat_count ", PL("cat",$cat_count), "\n";
# FORM PLURALS FOR SPECIFIC PARTS OF SPEECH
print PL_N("I",$N1), PL_V("saw",$N1),
PL_ADJ("my",$N2), PL_N("saw",$N2), "\n";
# DEAL WITH "0/1/N" -> "no/1/N" TRANSLATION:
print "There ", PL_V("was",$errors), NO(" error",$errors), "\n";
# USE DEFAULT COUNTS:
print NUM($N1,""), PL("I"), PL_V(" saw"), NUM($N2), PL_N(" saw");
print "There ", NUM($errors,''), PL_V("was"), NO(" error"), "\n";
# COMPARE TWO WORDS "NUMBER-INSENSITIVELY":
print "same\n" if PL_eq($word1, $word2);
print "same noun\n" if PL_N_eq($word1, $word2);
print "same verb\n" if PL_V_eq($word1, $word2);
print "same adj.\n" if PL_ADJ_eq($word1, $word2);
# ADD CORRECT "a" OR "an" FOR A GIVEN WORD:
print "Did you want ", A($thing), " or ", AN($idea), "\n";
# CONVERT NUMERALS INTO ORDINALS (i.e. 1->1st, 2->2nd, 3->3rd, etc.)
print "It was", ORD($position), " from the left\n";
# CONVERT NUMERALS TO WORDS (i.e. 1->"one", 101->"one hundred and one", etc.)
# IN A SCALAR CONTEXT: GET BACK A SINGLE STRING...
$words = NUMWORDS(1234); # "one thousand, two hundred and thirty-four"
$words = NUMWORDS(ORD(1234)); # "one thousand, two hundred and thirty-fourth"
# IN A LIST CONTEXT: GET BACK A LIST OF STRINGSi, ONE FOR EACH "CHUNK"...
@words = NUMWORDS(1234); # ("one thousand","two hundred and thirty-four")
# OPTIONAL PARAMETERS CHANGE TRANSLATION:
$words = NUMWORDS(12345, group=>1);
# "one, two, three, four, five"
$words = NUMWORDS(12345, group=>2);
# "twelve, thirty-four, five"
$words = NUMWORDS(12345, group=>3);
# "one twenty-three, forty-five"
$words = NUMWORDS(1234, 'and'=>'');
# "one thousand, two hundred thirty-four"
$words = NUMWORDS(1234, 'and'=>', plus');
# "one thousand, two hundred, plus thirty-four"
$words = NUMWORDS(555_1202, group=>1, zero=>'oh');
# "five, five, five, one, two, oh, two"
$words = NUMWORDS(555_1202, group=>1, one=>'unity');
# "five, five, five, unity, two, zero, two"
$words = NUMWORDS(123.456, group=>1, decimal=>'mark');
# "one two three mark four five six"
# LITERAL STYLE ONLY NAMES NUMBERS LESS THAN A CERTAIN THRESHOLD...
$words = NUMWORDS( 9, threshold=>10); # "nine"
$words = NUMWORDS( 10, threshold=>10); # "ten"
$words = NUMWORDS( 11, threshold=>10); # "11"
$words = NUMWORDS(1000, threshold=>10); # "1,000"
# JOIN WORDS INTO A LIST:
$list = WORDLIST("apple", "banana", "carrot");
# "apple, banana, and carrot"
$list = WORDLIST("apple", "banana");
# "apple and banana"
$list = WORDLIST("apple", "banana", "carrot", {final_sep=>""});
# "apple, banana and carrot"
# REQUIRE "CLASSICAL" PLURALS (EG: "focus"->"foci", "cherub"->"cherubim")
classical; # USE ALL CLASSICAL PLURALS
classical 1; # USE ALL CLASSICAL PLURALS
classical 0; # USE ALL MODERN PLURALS (DEFAULT)
classical 'zero'; # "no error" INSTEAD OF "no errors"
classical zero=>1; # "no error" INSTEAD OF "no errors"
classical zero=>0; # "no errors" INSTEAD OF "no error"
classical 'herd'; # "2 buffalo" INSTEAD OF "2 buffalos"
classical herd=>1; # "2 buffalo" INSTEAD OF "2 buffalos"
classical herd=>0; # "2 buffalos" INSTEAD OF "2 buffalo"
classical 'persons'; # "2 chairpersons" INSTEAD OF "2 chairpeople"
classical persons=>1; # "2 chairpersons" INSTEAD OF "2 chairpeople"
classical persons=>0; # "2 chairpeople" INSTEAD OF "2 chairpersons"
classical 'ancient'; # "2 formulae" INSTEAD OF "2 formulas"
classical ancient=>1; # "2 formulae" INSTEAD OF "2 formulas"
classical ancient=>0; # "2 formulas" INSTEAD OF "2 formulae"
# INTERPOLATE "PL()", "PL_N()", "PL_V()", "PL_ADJ()", A()", "AN()"
# "NUM()" AND "ORD()" WITHIN STRINGS:
print inflect("The plural of $word is PL($word)\n");
print inflect("I saw $cat_count PL(cat,$cat_count)\n");
print inflect("PL(I,$N1) PL_V(saw,$N1) PL(a,$N2) PL_N(saw,$N2)\n");
print inflect("NUM($N1,)PL(I) PL_V(saw) NUM($N2,)PL(a) PL_N(saw)\n");
print inflect("I saw NUM($cat_count) PL(cat)\n");
print inflect("There PL_V(was,$errors) NO(error,$errors)\n");
print inflect("There NUM($errors,)PL_V(was) NO(error)\n");
print inflect("Did you want A($thing) or AN($idea)\n");
print inflect("It was ORD($position) from the left\n");
# ADD USER-DEFINED INFLECTIONS (OVERRIDING INBUILT RULES):
def_noun "VAX" => "VAXen"; # SINGULAR => PLURAL
def_verb "will" => "shall", # 1ST PERSON SINGULAR => PLURAL
"will" => "will", # 2ND PERSON SINGULAR => PLURAL
"will" => "will"; # 3RD PERSON SINGULAR => PLURAL
def_adj "hir" => "their"; # SINGULAR => PLURAL
def_a "h"; # "AY HALWAYS SEZ 'HAITCH'!"
def_an "horrendous.*"; # "AN HORRENDOUS AFFECTATION"🌸 DESCRIPTION 🌸
maintenance mode alert, bestie: this module is strictly in maintenance mode now. Take a look at the newerLingua::EN::Inflexionmodule — it offers a cleaner and more convenient interface, has many more features (includingplural->singularinflexions), and is also much better tested. If you have existing code that relies onLingua::EN::Inflect, see the section of the documentation entitled"CONVERTING FROM LINGUA::EN::INFLECT".
so what do the exportable subroutines of Lingua::EN::Inflect actually do? They provide plural inflections, "a"/"an" selection for English words, and manipulation of numbers as words. it's giving grammar bestie with a Perl accent. 💖
Plural forms of all nouns, most verbs, and some adjectives are provided. Where appropriate, "classical" variants (for example: "brother" -> "brethren", "dogma" -> "dogmata", etc.) are also provided. obsessed with the range, honestly.
Pronunciation-based "a"/"an" selection is provided for all English words, and most initialisms.
It is also possible to inflect numerals (1,2,3) to ordinals (1st, 2nd, 3rd) and to English words ("one", "two", "three"). numbers getting a whole wardrobe change, iykyk.
In generating these inflections, Lingua::EN::Inflect follows the Oxford English Dictionary and the guidelines in Fowler's Modern English Usage, preferring the former where the two disagree. very "cited sources, no vibes-only guesses" of it.
The module is built around standard British spelling, but is designed to cope with common American variants as well. Slang, jargon, and other English dialects are not explicitly catered for. so yes, it's British-spelling-coded, but it's not gonna ghost the American variants.
Where two or more inflected forms exist for a single word (typically a "classical" form and a "modern" form), Lingua::EN::Inflect prefers the more common form (typically the "modern" one), unless "classical" processing has been specified (see "MODERN VS CLASSICAL INFLECTIONS"). default is modern, classical is the little switch you flip when you want the fancy historical fit. periodt.
So that's the whole opening section: the module is old-school but iconic, it follows OED and Fowler, it's British-spelling-coded but handles American variants, and if you're carrying legacy Lingua::EN::Inflect code you're absolutely seen. no cap, bestie. 💅
🌸 FORMING PLURALS 🌸
✨ Inflecting Plurals ✨
okay so literally every single one of the PL_... plural inflection subroutines takes the word you wanna inflect as its first argument and hands you back the matching inflection. big important note though: all of them expect the singular form of the word. pass in a plural and the results are undefined (and like, lowkey guaranteed to be wrong, no cap 🙈).
the PL_... subroutines also take an optional second argument — that's the grammatical "number" of the word (or of some other word that the word you're inflecting has to agree with). here's the tea ☕: if you supply the "number" argument and it's not 1 (or "one" or "a", or any other adjective that implies singular), you get the plural form back. if the number argument does indicate singularity, you just get the (uninflected) word itself back. and if you omit the number argument entirely? plural form, unconditionally, every time. slay.
the various subroutines are:
PL_N($;$)— the exportablePL_N()takes a singular English noun or pronoun and returns its plural. pronouns in the nominative case ("I"->"we") and the accusative case ("me"->"us") are handled, and so are possessive pronouns ("mine"->"ours"). pronouns ate, fr fr 🫶PL_V($;$)— the exportablePL_V()takes the singular form of a conjugated verb (meaning one that's already in the correct "person" and "mood") and returns the corresponding plural conjugation.PL_ADJ($;$)— the exportablePL_ADJ()takes the singular form of certain types of adjectives and returns the matching plural form. the adjectives that are correctly handled include: "numerical" adjectives ("a"->"some"), demonstrative adjectives ("this"->"these","that"->"those"), and possessives ("my"->"our","cat's"->"cats'","child's"->"childrens'", etc.)PL($;$)— the exportablePL()takes a singular English noun, pronoun, verb, or adjective and returns its plural form. where a word has more than one inflection depending on its part of speech (for example, the noun"thought"inflects to"thoughts", while the verb"thought"inflects to"thought"), the (singular) noun sense wins over the (singular) verb sense.
so like, PL("knife") will return "knives" ("knife" having been treated as a singular noun), whereas PL("knifes") will return "knife" ("knifes" having been treated as a 3rd person singular verb). iconic behavior honestly 💅
the inherent ambiguity of these cases is giving "pick a lane" energy, which suggests that where the part of speech is known, you should use PL_N, PL_V, and PL_ADJ instead of PL. periodt.
💡 also note that all these subroutines ignore any whitespace surrounding the word being inflected, but they preserve that whitespace when the result comes back. for example,PL(" cat ")returns" cats ". the spaces stay, bestie, they're part of the vibe.
🔢 Numbered plurals 🔢
the PL_... subroutines return only the inflected word — not the count you used to inflect it. so to produce "I saw 3 ducks", you gotta do this whole thing:
print "I saw $N ", PL_N($animal,$N), "\n";since the usual purpose of producing a plural is to make it agree with a preceding count, Lingua::EN::Inflect provides an exportable subroutine (NO($;$)) which, given a word and a(n optional) count, returns the count followed by the correctly inflected word. so the previous example can be rewritten as:
print "I saw ", NO($animal,$N), "\n";and bonus: if the count is zero (or some other term that implies zero, like "zero", "nil", etc.) the count gets replaced by the word "no". so if $N had the value zero, the previous example would print the somewhat more elegant:
I saw no animalsinstead of:
I saw 0 animals🎀 fun fact: the subroutine's name is a pun — it returns either a number (a No.) or a "no", sitting right in front of the inflected word. iykyk.
🎀 Wordy and comma'd plurals 🎀
the NO() subroutine takes an optional third argument: a hash of named options that configure its behaviour. let's get into it 💖
the words_below option tells NO() what other numbers (i.e. apart from zero) it should convert to words. for example:
for my $count (0..12) {
print NO('cat', $count, {words_below => 10}), "\n";
}would print:
no cats
one cat
two cats
three cats
four cats
five cats
six cats
seven cats
eight cats
nine cats
10 cats
11 cats
12 catsthe comma and comma_every options determine whether or not the numbers produced by NO() have commas in them. that is:
2001 space odysseysversus:
2,001 space odysseysnormally, numbers are produced without commas, but if comma or comma_every is specified, then commas get added as requested.
the comma option specifies which character to use as a comma. it defaults to ',', but it may be set to anything convenient:
print NO('Euro', $amount, {comma=>'.'});
# prints: 1.000.000 Eurosthe comma_every option specifies how many characters go between commas. it defaults to 3, but it may be set to any positive number:
print NO('Euro', $amount, {comma_every=>4});
# prints: 100,0000 Eurosand yes, you can set both options at once if you're feeling spicy 🌶️:
print NO('Euro', $amount, {comma_every=>2, comma=>'_'});
# prints: 1_00_00_00 Euros💀 Reducing the number of counts required 💀
in some contexts, needing to supply an explicit count to the various PL_... subroutines is just tiresome repetition, and honestly? mood. for example:
print PL_ADJ("This",$errors), PL_N(" error",$errors),
PL_V(" was",$errors), " fatal.\n";Lingua::EN::Inflect therefore provides an exportable subroutine (NUM($;$)) that may be used to set a persistent "default number" value. if such a value is set, it's subsequently used whenever an optional second "number" argument is omitted. and the default value set this way can be removed again by calling NUM() with no arguments. so we could rewrite the previous example like this:
NUM($errors);
print PL_ADJ("This"), PL_N(" error"), PL_V(" was"), "fatal.\n";
NUM();normally, NUM() returns its first argument, so it can also be "inlined" in contexts like:
print NUM($errors), PL_N(" error"), PL_V(" was"), " detected.\n"
print PL_ADJ("This"), PL_N(" error"), PL_V(" was"), "fatal.\n"
if $severity > 1;however, in certain contexts (see "INTERPOLATING INFLECTIONS IN STRINGS") it's preferable for NUM() to return an empty string. that's why NUM() provides an optional second argument. if that argument is supplied (that is, if it's defined) and evaluates to false, NUM returns an empty string instead of its first argument. for example:
print NUM($errors,0), NO("error"), PL_V(" was"), " detected.\n";
print PL_ADJ("This"), PL_N(" error"), PL_V(" was"), "fatal.\n"
if $severity > 1;👑 Number-insensitive equality 👑
Lingua::EN::Inflect also serves up a solution to the problem of comparing words of differing plurality, via the exportable subroutines PL_eq($$), PL_N_eq($$), PL_V_eq($$), and PL_ADJ_eq($$). each of these subroutines takes two strings and compares them using the corresponding plural-inflection subroutine (PL(), PL_N(), PL_V(), and PL_ADJ() respectively).
the comparison returns true if:
- the strings are
"eq"-equal, or - one string is
"eq"-equal to a plural form of the other, or - the strings are two different plural forms of the one word.
hence all of the following return true:
PL_eq("index","index") # RETURNS "eq"
PL_eq("index","indexes") # RETURNS "s:p"
PL_eq("index","indices") # RETURNS "s:p"
PL_eq("indexes","index") # RETURNS "p:s"
PL_eq("indices","index") # RETURNS "p:s"
PL_eq("indices","indexes") # RETURNS "p:p"
PL_eq("indexes","indices") # RETURNS "p:p"
PL_eq("indices","indices") # RETURNS "eq"as the comments up there show, the actual value returned by the various PL_eq subroutines encodes which of the three equality rules succeeded: "eq" is returned if the strings were identical, "s:p" if the strings were singular and plural respectively, "p:s" for plural and singular, and "p:p" for two distinct plurals. inequality is indicated by returning an empty string.
⚠️ also it should be noted that two distinct singular words which happen to take the same plural form are not considered equal, and neither are cases where one (singular) word's plural is the other (plural) word's singular. so all of the following return false:
PL_eq("base","basis") # ALTHOUGH BOTH -> "bases"
PL_eq("syrinx","syringe") # ALTHOUGH BOTH -> "syringes"
PL_eq("she","he") # ALTHOUGH BOTH -> "they"
PL_eq("opus","operas") # ALTHOUGH "opus" -> "opera" -> "operas"
PL_eq("taxi","taxes") # ALTHOUGH "taxi" -> "taxis" -> "taxes"and note too that, although the comparison is "number-insensitive", it is not case-insensitive (that is, PL("time","Times") returns false). to get both number and case insensitivity, prefix both arguments with lc (that is, PL(lc "time", lc "Times") returns true). lowercase bestie, always 🦋
🌈 OTHER VERB FORMS 🌈
🧚 Present participles 🧚
Lingua::EN::Inflect also provides the PART_PRES subroutine, which can take a 3rd person singular verb and correctly inflect it to its present participle. look at her go:
PART_PRES("runs") # "running"
PART_PRES("loves") # "loving"
PART_PRES("eats") # "eating"
PART_PRES("bats") # "batting"
PART_PRES("spies") # "spying"literally just vibes and correct grammar 💜
💅 PROVIDING INDEFINITE ARTICLES 💅
🌸 Selecting indefinite articles 🌸
Okay bestie, so Lingua::EN::Inflect gives you two exportable subroutines — A($;$) and AN($;$) — and they will correctly prepend the appropriate indefinite article to a word depending on how it’s pronounced. Slay. For example:
A("cat") # -> "a cat"
AN("cat") # -> "a cat"
A("euphemism") # -> "a euphemism"
A("Euler number") # -> "an Euler number"
A("hour") # -> "an hour"
A("houri") # -> "a houri"The two subroutines are literally identical in function and may be used interchangeably. The only reason two versions exist is to make code like this read nicer:
print "That is ", AN($errortype), " error\n;
print "That is ", A($fataltype), " fatal error\n;Note that in both cases the actual article provided depends only on the pronunciation of the first argument, not on the name of the subroutine. The way that works is lowkey iconic.
A() and AN() will ignore any indefinite article that already exists at the start of the string. So this:
@half_arked = (
"a elephant",
"a giraffe",
"an ewe",
"a orangutan",
);
print A($_), "\n" for @half_arked;
# prints:
# an elephant
# a giraffe
# a ewe
# an orangutanA() and AN() both take an optional second argument. As with the "PL_..." subroutines, this second argument is a "number" specifier. If its value is 1 (or some other value implying singularity), A() and AN() insert "a" or "an" as appropriate. If the number specifier implies plurality, A() and AN() insert the actual second argument instead. For example:
A("cat",1) # -> "a cat"
A("cat",2) # -> "2 cat"
A("cat","one") # -> "one cat"
A("cat","no") # -> "no cat"Note that, as implied by the previous examples, A() and AN() both assume that their job is merely to provide the correct qualifier for a word (that is: "a", "an", or the specified count). In other words, they assume that the word they are given has already been correctly inflected for plurality. Hence, if $N has the value 2, then:
print A("cat",$N);prints "2 cat", instead of "2 cats". The correct approach is to use:
print A(PL("cat",$N),$N);or, better still:
print NO("cat",$N);Note too that, like the various "PL_..." subroutines, whenever A() and AN() are called with only one argument they are subject to the effects of any preceding call to NUM(). Hence, another possible solution is:
NUM($N);
print A(PL("cat"));🦋 Indefinite articles and initialisms 🦋
"Initialisms" (sometimes inaccurately called "acronyms") are terms which have been formed from the initial letters of words in a phrase (for example, "NATO", "NBL", "S.O.S.", "SCUBA", etc.)
Such terms present a particular challenge when selecting between "a" and "an", since they are sometimes pronounced as if they were a single word ("nay-tow", "sku-ba") and sometimes as a series of letter names ("en-eff-ell", "ess-oh-ess").
A() and AN() cope with this dichotomy using a series of inbuilt rules, which may be summarized as:
- If the word starts with a single letter, followed by a period or dash (for example,
"R.I.P.","C.O.D.","e-mail","X-ray","T-square"), then choose the appropriate article for the sound of the first letter ("an R.I.P.","a C.O.D.","an e-mail","an X-ray","a T-square"). - If the first two letters of the word are capitals, consonants, and do not appear at the start of any known English word, (for example,
"LCD","XML","YWCA"), then once again choose"a"or"an"depending on the sound of the first letter ("an LCD","an XML","a YWCA"). - Otherwise, assume the string is a capitalized word or a pronounceable initialism (for example,
"LED","OPEC","FAQ","UNESCO"), and therefore takes"a"or"an"according to the (apparent) pronunciation of the entire word ("a LED","an OPEC","a FAQ","a UNESCO").
Note that rules 1 and 3 together imply that the presence or absence of punctuation may change the selection of indefinite article for a particular initialism (for example, "a FAQ" but "an F.A.Q."). The drama of it all 💅
💜 Indefinite articles and "soft H's" 💜
Words beginning in the letter 'H' present another type of difficulty when selecting a suitable indefinite article. In a few such words (for example, "hour", "honour", "heir") the 'H' is not voiced at all, and so such words inflect with "an". The remaining cases ("voiced H's") may be divided into two categories: "hard H's" (such as "hangman", "holograph", "hat", etc.) and "soft H's" (such as "hysterical", "horrendous", "holy", etc.)
Hard H's always take "a" as their indefinite article, and soft H's normally do so as well. But some English speakers prefer "an" for soft H's (although the practice is now generally considered an affectation, rather than a legitimate grammatical alternative).
At present, the A() and AN() subroutines ignore soft H's and use "a" for any voiced 'H'. The author would, however, welcome feedback on this decision (envisaging a possible future "soft H" mode).
👑 INFLECTING ORDINALS 👑
Occasionally it is useful to present an integer value as an ordinal rather than as a numeral. For example:
Enter password (1st attempt): ********
Enter password (2nd attempt): *********
Enter password (3rd attempt): *********
No 4th attempt. Access denied.To this end, Lingua::EN::Inflect provides the ORD() subroutine. <ORD()> takes a single argument and forms its ordinal equivalent. If the argument isn't a numerical integer, it just adds "-th".
💖 CONVERTING NUMBERS TO WORDS 💖
Okay bestie, so the exportable subroutine NUMWORDS takes a number (cardinal or ordinal) and returns an English representation of that number. In a scalar context a string is returned. Hence:
use Lingua::EN::Inflect qw( NUMWORDS );
$words = NUMWORDS(1234567);puts the string:
"one million, two hundred and thirty-four thousand, five hundred and sixty-seven"into $words.
In a list context each comma-separated chunk is returned as a separate element. Hence:
@words = NUMWORDS(1234567);puts the list:
("one million",
"two hundred and thirty-four thousand",
"five hundred and sixty-seven")into @words.
Note that this also means that:
print NUMWORDS(1234567);will (misprint) print:
one milliontwo hundred and thirty-four thousandfive hundred and sixty-sevenTo get readable output, make sure the call in in scalar context:
print scalar NUMWORDS(1234567);Non-digits (apart from an optional leading plus or minus sign, any decimal points, and ordinal suffixes -- see below) are silently ignored, so the following all produce identical results:
NUMWORDS(5551202);
NUMWORDS(5_551_202);
NUMWORDS("5,551,202");
NUMWORDS("555-1202");That last case is a little awkward since it's almost certainly a phone number, and "five million, five hundred and fifty-one thousand, two hundred and two" probably isn't what's wanted.
To overcome this, NUMWORDS() takes an optional named argument, 'group', which changes how numbers are translated. The argument must be a positive integer less than four, which indicated how the digits of the number are to be grouped. If the argument is 1, then each digit is translated separately. If the argument is 2, pairs of digits (starting from the left) are grouped together. If the argument is 3, triples of numbers (again, from the left) are grouped. Hence:
NUMWORDS("555-1202", group=>1)returns "five, five, five, one, two, zero, two", whilst:
NUMWORDS("555-1202", group=>2)returns "fifty-five, fifty-one, twenty, two", and:
NUMWORDS("555-1202", group=>3)returns "five fifty-five, one twenty, two".
Phone numbers are often written in words as "five..five..five..one..two..zero..two", which is also easy to achieve:
join '..', NUMWORDS("555-1202", group=>1)NUMWORDS also handles decimal fractions. Hence:
NUMWORDS("1.2345")returns "one point two three four five" in a scalar context and "("one","point","two","three","four","five")" in an array context. Exponent form (1.234e56) is not yet handled.
Multiple decimal points are only translated in one of the "grouping" modes. Hence:
NUMWORDS(101.202.303)returns "one hundred and one point two zero two three zero three", whereas:
NUMWORDS(101.202.303, group=>1)returns "one zero one point two zero two point three zero three".
The digit '0' is unusual in that in may be translated to English as "zero", "oh", or "nought". To cater for this diversity, NUMWORDS may be passed a named argument, 'zero', which may be set to the desired translation of '0'. For example:
print join "..", NUMWORDS("555-1202", group=>3, zero=>'oh')prints "five..five..five..one..two..oh..two". By default, zero is rendered as "zero".
Likewise, the digit '1' may be rendered as "one" or "a/an" (or very occasionally other variants), depending on the context. So there is a 'one' argument as well:
print NUMWORDS($_, one=>'a solitary', zero=>'no more'),
PL(" bottle of beer on the wall\n", $_)
for (3,2,1,0);
# prints:
# three bottles of beer on the wall
# two bottles of beer on the wall
# a solitary bottle of beer on the wall
# no more bottles of beer on the wallCare is needed if the word "a/an" is to be used as a 'one' value. Unless the next word is known in advance, it's almost always necessary to use the A function as well:
print A( NUMWORDS(1, one=>'a') . " $_\n")
for qw(cat aardvark ewe hour);
# prints:
# a cat
# an aardvark
# a ewe
# an hourAnother major regional variation in number translation is the use of "and" in certain contexts. The named argument 'and' allows the programmer to specify how "and" should be handled. Hence:
print scalar NUMWORDS("765", 'and'=>'')prints "seven hundred sixty-five", instead of "seven hundred and sixty-five". By default, the "and" is included.
The translation of the decimal point is also subject to variation (with "point", "dot", and "decimal" being the favorites). The named argument 'decimal' allows the programmer to how the decimal point should be rendered. Hence:
print scalar NUMWORDS("666.124.64.101", group=>3, decimal=>'dot')prints "six sixty-six, dot, one twenty-four, dot, sixty-four, dot, one zero one" By default, the decimal point is rendered as "point".
NUMWORDS also handles the ordinal forms of numbers. So:
print scalar NUMWORDS('1st');
print scalar NUMWORDS('3rd');
print scalar NUMWORDS('202nd');
print scalar NUMWORDS('1000000th');print:
first
third
two hundred and twenty-second
one millionthTwo common idioms in this regard are:
print scalar NUMWORDS(ORD($number));and:
print scalar ORD(NUMWORDS($number));These are identical in effect, except when $number contains a decimal:
$number = 99.09;
print scalar NUMWORDS(ORD($number)); # ninety-ninth point zero nine
print scalar ORD(NUMWORDS($number)); # ninety-nine point zero ninthUse whichever you feel is most appropriate.
🎀 CONVERTING LISTS OF WORDS TO PHRASES 🎀
When creating a list of words, commas are used between adjacent items, except if the items contain commas, in which case semicolons are used. But if there are less than two items, the commas/semicolons are omitted entirely. The final item also has a conjunction (usually "and" or "or") before it. And although it's technically incorrect (and sometimes misleading), some people prefer to omit the comma before that final conjunction, even when there are more than two items.
That's complicated enough to warrant its own subroutine: WORDLIST(). This subroutine expects a list of words, possibly with one or more hash references containing options. It returns a string that joins the list together in the normal English usage. For example:
print "You chose ", WORDLIST(@selected_items), "\n";
# You chose barley soup, roast beef, and Yorkshire pudding
print "You chose ", WORDLIST(@selected_items, {final_sep=>""}), "\n";
# You chose barley soup, roast beef and Yorkshire pudding
print "Please chose ", WORDLIST(@side_orders, {conj=>"or"}), "\n";
# Please chose salad, vegetables, or ice-creamThe available options are:
conj— final conjunction; default value"and"sep— inter-item separator; default value","last_sep— final separator; default value is the value of the'sep'option
🦋 INTERPOLATING INFLECTIONS IN STRINGS 🦋
By far the commonest use of the inflection subroutines is to produce message strings for various purposes. For example:
print NUM($errors), PL_N(" error"), PL_V(" was"), " detected.\n";
print PL_ADJ("This"), PL_N(" error"), PL_V(" was"), "fatal.\n"
if $severity > 1;Unfortunately the need to separate each subroutine call detracts significantly from the readability of the resulting code. To ameliorate this problem, Lingua::EN::Inflect provides an exportable string-interpolating subroutine (inflect($)), which recognizes calls to the various inflection subroutines within a string and interpolates them appropriately.
Using "inflect" the previous example could be rewritten:
print inflect "NUM($errors) PL_N(error) PL_V(was) detected.\n";
print inflect "PL_ADJ(This) PL_N(error) PL_V(was) fatal.\n"
if $severity > 1;Note that "inflect" also correctly handles calls to the NUM() subroutine (whether interpolated or antecedent). The inflect() subroutine has a related extra feature, in that it automatically cancels any "default number" value before it returns its interpolated string. This means that calls to NUM() which are embedded in an inflect()-interpolated string do not "escape" and interfere with subsequent inflections.
💅 MODERN VS CLASSICAL INFLECTIONS 💅
Okay so here's the tea, bestie: some words — mostly the ones with Latin or Ancient Greek DNA — can go plural two ways. You can slap the standard English -s on them, or you can go full ancestral and use their original Latin/Greek inflections. Behold:
PL("stigma") # -> "stigmas" or "stigmata"
PL("torus") # -> "toruses" or "tori"
PL("index") # -> "indexes" or "indices"
PL("millennium") # -> "millenniums" or "millennia"
PL("ganglion") # -> "ganglions" or "ganglia"
PL("octopus") # -> "octopuses" or "octopodes"Lingua::EN::Inflect handles this with a whole "alternate state" of inflection called "classical mode". Default setting? Contemporary English plurals, periodt. But once classical mode is invoked, you get the more traditional plural forms back instead. It's giving vintage. 🏛️
The exportable subroutine classical() is the one holding the aux cord:
- Called with no arguments → it unconditionally invokes classical mode. No thoughts, just vibes.
- Called with a single argument → it turns all classical inflects on or off, depending on whether that argument is true or false.
- Called with two or more arguments → those arguments specify which aspects of classical behaviour are to be used. Picky picky, love that.
Thus:
classical; # SWITCH ON CLASSICAL MODE
print PL("formula"); # -> "formulae"
classical 0; # SWITCH OFF CLASSICAL MODE
print PL("formula"); # -> "formulas"
classical $cmode; # CLASSICAL MODE IFF $cmode
print PL("formula"); # -> "formulae" (IF $cmode)
# -> "formulas" (OTHERWISE)
classical herd=>1; # SWITCH ON CLASSICAL MODE FOR "HERD" NOUNS
print PL("wilderbeest"); # -> "wilderbeest"
classical names=>1; # SWITCH ON CLASSICAL MODE FOR NAMES
print PL("sally"); # -> "sallies"
print PL("Sally"); # -> "Sallys"⚠️ Important caveat though — classical() has no effect on the inflection of words that are now fully assimilated. So like:
PL("forum") # ALWAYS -> "forums"
PL("criterion") # ALWAYS -> "criteria"Also: LEI assumes a capitalized word is a person's name. So it pluralizes according to the rules for names — which is that you don't inflect, you just add -s or -es. You can turn that behaviour off (it's on by default, even when the module isn't in classical mode, just so we're clear) by calling classical(names=>0). 🫶
🛠️ USER-DEFINED INFLECTIONS 🛠️
🌸 Adding plurals at run-time 🌸
Lingua::EN::Inflect provides five exportable subroutines that let you override the module's behaviour for specific cases. Five! We love options. Let's meet them.
✨ def_noun($$) ✨
def_noun takes a pair of string arguments: the singular and plural forms of the noun you're specifying.
The singular form specifies a pattern to be interpolated (as m/^(?:$first_arg)$/i). Any noun matching this pattern is then replaced by the string in the second argument.
The second argument specifies a string which is interpolated after the match succeeds, and is then used as the plural form. Like so:
def_noun 'cow' => 'kine';
def_noun '(.+i)o' => '$1i';
def_noun 'spam(mer)?' => '\\$\\%\\@#\\$\\@#!!';Note that both arguments should usually be specified in single quotes, so they're not interpolated when you specify them, but later (when words are compared to them). And as that last example is screaming at you, care also needs to be taken with certain characters in the second argument, so they don't get unintentionally interpolated during comparison. 💀
The second argument string may also specify a second variant of the plural form, used when "classical" plurals have been requested. The beginning of the second variant is marked by a '|' character:
def_noun 'cow' => 'cows|kine';
def_noun '(.+i)o' => '$1os|$1i';
def_noun 'spam(mer)?' => '\\$\\%\\@#\\$\\@#!!|varmints';If no classical variant is given, the specified plural form is used in both normal and "classical" modes. One form, two modes, efficient queen. 👑
If the second argument is undef instead of a string, then the current user definition for the first argument is removed, and the standard plural inflection(s) restored. Pop it like it never happened.
And in all cases, later plural definitions for a particular singular form replace earlier definitions of the same form. For example:
# FIRST, HIDE THE MODERN FORM....
def_noun 'aviatrix' => 'aviatrices';
# LATER, HIDE THE CLASSICAL FORM...
def_noun 'aviatrix' => 'aviatrixes';
# FINALLY, RESTORE THE DEFAULT BEHAVIOUR...
def_noun 'aviatrix' => undef;Special care is also required when defining general patterns and associated specific exceptions: put the more specific cases after the general pattern. For example:
def_noun '(.+)us' => '$1i'; # EVERY "-us" TO "-i"
def_noun 'bus' => 'buses'; # EXCEPT FOR "bus"This "try-most-recently-defined-first" approach to matching user-defined words is also used by def_verb, def_a and def_an. Consistency, we stan. ✨
✨ def_verb($$$$$$) ✨
def_verb takes three pairs of string arguments — that is, six arguments in total — specifying the singular and plural forms of the three "persons" of the verb.
As with def_noun, the singular forms are specifications of run-time-interpolated patterns, whilst the plural forms are specifications of (up to two) run-time-interpolated strings:
def_verb 'am' => 'are',
'are' => 'are|art',
'is' => 'are';
def_verb 'have' => 'have',
'have' => 'have',
'ha(s|th)' => 'have';Note that as with def_noun, modern/classical variants of plurals may be separately specified, subsequent definitions replace previous ones, and undef'ed plural forms revert to the standard behaviour. Same energy, different grammar. 🦋
✨ def_adj($$) ✨
def_adj takes a pair of string arguments, which specify the singular and plural forms of the adjective being defined.
As with def_noun and def_adj, the singular forms are specifications of run-time-interpolated patterns, whilst the plural forms are specifications of (up to two) run-time-interpolated strings:
def_adj 'this' => 'these',
def_adj 'red' => 'red|gules',As previously, modern/classical variants of plurals may be separately specified, subsequent definitions replace previous ones, and undef'ed plural forms revert to the standard behaviour. 🎀
✨ def_a($) and def_an($) ✨
def_a and def_an each take a single argument, which specifies a pattern. If a word passed to A() or AN() matches this pattern, it will be prefixed (unconditionally) with the corresponding indefinite article. Example time:
def_a 'error';
def_a 'in.+';
def_an 'mistake';
def_an 'error';As with the other def_... subroutines, such redefinitions are sequential in effect, so that — after the above example — "error" will be inflected with "an". Last one wins, every time. 🏆
🧚 The $HOME/.inflectrc file 🧚
When it's imported, Lingua::EN::Inflect executes (as Perl code) the contents of any file named .inflectrc which it finds in the directory where Lingua/EN/Inflect.pm is installed, or in the current home directory ($ENV{HOME}), or in both. Double trouble. 😭
Heads up: that code is executed within the Lingua::EN::Inflect namespace. So like, know that before you go feral in there.
Hence the user, or the local Perl guru, can make appropriate calls to def_noun, def_verb, etc. in one of these .inflectrc files, to permanently and universally modify the behaviour of the module. Forever-forever. For example:
> cat /usr/local/lib/perl5/Text/Inflect/.inflectrc
def_noun "UNIX" => "UN*X|UNICES";
def_verb "teco" => "teco", # LITERALLY: "to edit with TECO"
"teco" => "teco",
"tecos" => "teco";
def_a "Euler.*"; # "Yewler" TURNS IN HIS GRAVEAnd one last thing: calls to the def_... subroutines from within a program will take precedence over the contents of the home directory .inflectrc file — which in turn takes precedence over the system-wide .inflectrc file. Hierarchy! Know your place (affectionate). 💅
💅 DIAGNOSTICS 💅
okay so when Perl loads a .inflectrc file and the Perl code inside is invalid — syntactically or otherwise — it throws an appropriate fatal error. a common glow-up fail? not ending the file with something that evaluates to true (just like the five def_... subroutines do). 💀
Using the five def_... subroutines directly in a program can also cause fatal diagnostics if a (singular) pattern or an interpolated (plural) string is somehow invalid. the specific diagnostics for user-defined inflections are:
"Bad user-defined singular pattern:\n\t %s"— the singular form of a user-defined noun or verb (as defined by a call todef_noun,def_verb,def_adj,def_aordef_an) is not a valid Perl regular expression. the actual Perl error message is also given."Bad user-defined plural string: '%s'"— the plural form(s) of a user-defined noun or verb (as defined by a call todef_noun,def_verbordef_adj) is not a valid Perl interpolated string (usually because it interpolates some undefined variable)."Bad .inflectrc file (%s):\n %s"— some other problem occurred while loading the named local or global.inflectrcfile. the Perl error message (including the line number) is also given.
There are no diagnosable run-time error conditions for the actual inflection subroutines, except NUMWORDS and hence no run-time diagnostics. if the inflection subroutines can’t form a plural via a user-definition or an inbuilt rule, they just “guess” the commonest English inflection: adding -s for nouns, removing -s for verbs, and no inflection for adjectives. 🫶
Lingua::EN::Inflect::NUMWORDS() can “die” with these messages:
"Bad grouping option: %s"— the optional argument toNUMWORDS()wasn’t1,2or3."Number out of range"—NUMWORDS()was passed a number larger than the number represented by 3006 consecutive nines. the words representing that number are 63,681 characters long, including commas and spaces. if you’re interested in the actual value, seet/numwords.t.
The reference for the names is http://en.wikipedia.org/wiki/Names_of_large_numbers. there are no names for any higher numbers. periodt. ✨
🦋 OTHER ISSUES 🦋
🎀 2nd Person precedence 🎀
If a verb has identical 1st and 2nd person singular forms, but different 1st and 2nd person plural forms, then when its plural is constructed, the 2nd person plural form is always preferred. no cap.
The author is not currently aware of any such verbs in English, but is not quite arrogant enough to assume ipso facto that none exist. 😭
🌸 Nominative precedence 🌸
The singular pronoun it is a whole special problem because its plural form can vary, depending on its “case”. for example:
It ate my homework -> They ate my homework
It ate it -> They ate them
I fed my homework to it -> I fed my homework to themAs a consequence of this ambiguity, PL() or PL_N have been implemented so that they always return the nominative plural (that is, they). main character pronoun energy, honestly. 👑
However, when asked for the plural of an unambiguously accusative it (namely, PL("to it"), PL_N("from it"), PL("with it"), etc.), both subroutines will correctly return the accusative plural ("to them", "from them", "with them", etc.). slay. 💅
⭐ The plurality of zero ⭐
The rules governing the choice between:
There were no errors.and
There was no error.are complex and often depend more on intent rather than content. hence it is infeasible to specify such rules algorithmically. 💀
Therefore, Lingua::EN::Text contents itself with the following compromise: if the governing number is zero, inflections always return the plural form unless the appropriate “classical” inflection is in effect, in which case the singular form is always returned. iykyk.
Thus, the sequence:
NUM(0);
print inflect "There PL(was) NO(choice)";produces "There were no choices", whereas:
classical 'zero'; # or: classical(zero=>1);
NUM(0);
print inflect "There PL(was) NO(choice)";it will print "There was no choice". the zero saga is real. 🍓
🧚 Homographs with heterogeneous plurals 🧚
Another context where intent (and not content) sometimes determines plurality is when two distinct meanings of a word require different plurals. for example:
Three basses were stolen from the band's equipment trailer.
Three bass were stolen from the band's aquarium.
I put the mice next to the cheese.
I put the mouses next to the computers.
Several thoughts about leaving crossed my mind.
Several thought about leaving across my lawn.Lingua::EN::Inflect handles such words in two ways:
- If both meanings of the word are the same part of speech (for example,
bassis a noun in both sentences above), then one meaning is chosen as the “usual” meaning, and only that meaning’s plural is ever returned by any of the inflection subroutines. - If each meaning of the word is a different part of speech (for example,
thoughtis both a noun and a verb), then the noun’s plural is returned byPL()andPL_N()and the verb’s plural is returned only byPL_V().
Such contexts are, fortunately, uncommon (particularly “same-part-of-speech” examples). an informal study of nearly 600 “difficult plurals” indicates that PL() can be relied upon to “get it right” about 98% of the time (although, of course, ichthyophilic guitarists or cyber-behaviouralists may experience higher rates of confusion). honestly iconic research. 🔥
If the choice of a particular “usual inflection” is considered inappropriate, it can always be reversed with a preliminary call to the corresponding def_... subroutine. 🫶
🌈 NOTE 🌈
I’m not taking any further correspondence on:
"octopi"— despite the populist pandering of certain New World dictionaries, the plural is"octopuses"or (for the pedantic classicist)"octopodes". the suffix-pusis Greek, not Latin, so the plural is-podes, notpi. not me getting into it again. 💀"virus"— had no plural in Latin (possibly because it was a mass noun). the only plural is the Anglicized"viruses".
👑 AUTHOR 👑
Damian Conway (damian@conway.org)
😭 BUGS AND IRRITATIONS 😭
The endless inconsistencies of English.
(Please report words for which the correct plural or indefinite article is not formed, so that the reliability of Lingua::EN::Inflect can be improved.) 🙈
🎀 COPYRIGHT 🎀
Copyright (c) 1997-2009, Damian Conway. All Rights Reserved.
This module is free software. It may be used, redistributed
and/or modified under the same terms as Perl itself.and that’s the whole page, bestie! 🌈 this was Lingua:...:Inflect(3) from perl v5.42.0, dated 2020-12-09. periodt. 💅
📦 where this page comes from
- opensuse-leap 16.0: perl-Lingua-EN-Inflect 1.905-bp160.1.12 · Artistic-1.0 OR GPL-1.0-or-later
- 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms