Pluralizer
Paste English nouns or short noun phrases, one per line, and choose plural or singular. The pluralizer applies the spelling rules (-s, -es, -ies), knows a list of irregular and unchanging nouns, keeps your capitalization and changes only the head noun of a phrase.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Paste one noun or noun phrase per line.
- Choose Plural or Singular.
- Copy the result. Empty lines and capitalization (cat, Cat, CAT) are kept.
Rules it applies
To make a plural, in this order:
- Unchanged nouns stay as they are: sheep, fish, deer, series, species, aircraft, and uncountable words such as information, software or advice.
- Irregular nouns come from a list: child → children, person → people, mouse → mice, criterion → criteria, analysis → analyses, knife → knives, potato → potatoes.
- -s, -x, -z, -ch, -sh add -es: bus → buses, box → boxes, church → churches.
- Consonant + y becomes -ies: city → cities; vowel + y adds -s: key → keys.
- Everything else adds -s: photo → photos, roof → roofs.
The singular reverses the same rules: cities → city, boxes → box, houses → house, wolves → wolf.
Worked example
The sample list becomes: cats, boxes, cities, children, mice, sheep, knives, analyses, credit cards, mothers-in-law.
Switch to Singular and paste the result back to get the original list again.
Tips
- Phrases change their last word, so put the noun last: “user account” → “user accounts”.
- For code, convert the words first and then change the case with the case converter (user_accounts, UserAccounts).
- The tool works with English only; Russian or Spanish nouns follow other rules.
Frequently asked questions
What are the rules for English plurals?
Most nouns add -s (cat → cats). Nouns ending in s, x, z, ch or sh add -es (box → boxes), a consonant plus y becomes -ies (city → cities), while a vowel plus y just adds -s (day → days). Irregular nouns such as child, mouse, knife or analysis have their own forms.
Which irregular plurals does it know?
The common ones from old English (man, woman, child, tooth, foot, mouse, goose, ox), Latin and Greek loans (cactus, criterion, phenomenon, analysis, appendix, matrix), f to ves (knife, leaf, wolf), o to oes (potato, hero, echo) and nouns that do not change (sheep, fish, deer, species, series).
How are noun phrases and compounds handled?
The last word of a phrase changes (credit card → credit cards). In compounds with -in-law or -by the first word changes (mother-in-law → mothers-in-law, passer-by → passers-by).
Is the result always right?
For regular nouns and the listed irregular ones, yes. Rare words, words with two accepted plurals (indexes and indices, cactuses and cacti) and words that look plural (news, lens) may need a check; the tool picks one form.