English Singular/Plural — Regular and Irregular Rules Together
Most English nouns pluralize by adding '-s' or '-es', but there are several branching rules: a consonant plus 'y' becomes '-ies', some words ending in f/fe switch to '-ves', and a good number of nouns change shape entirely — man to men, child to children. This tool combines a dictionary of common irregular nouns with regular-rule logic to convert your word into the form you need.
Supported rules:
- Regular: cat to cats, box to boxes
- Consonant + y: city to cities
- f/fe to ves (some): leaf to leaves, knife to knives
- Irregular: man to men, child to children, mouse to mice, and more
- Same for singular and plural: sheep, fish, deer
Use cases:
- Quickly checking noun forms while writing in English
- Learning plural rules as an English learner
- Avoiding grammar mistakes in documents and presentations
Words missing from the built-in dictionary are estimated using standard English pluralization rules, so double-check results for uncommon loanwords or technical terms.
FAQ
Yes. About 30 common irregular plurals such as man to men, child to children, and mouse to mice are handled with a built-in dictionary. Words not in the dictionary fall back to regular rules (-s, -es, -ies, etc.).
Words whose singular and plural forms are identical are returned unchanged, and the result note shows 'same for singular and plural'.
Click either the 'Pluralize' or 'Singularize' button depending on the direction you want. If the word is already in the target form, it's shown as-is.