Irregular Plural Nouns
Nouns that don't follow regular -s/-es plural rules
When to Use Irregular Plural Nouns
- •Vowel change plurals: man → men, woman → women, foot → feet, tooth → teeth, goose → geese, mouse → mice.
- •-en plurals: child → children, ox → oxen.
- •Same singular and plural: sheep, fish, deer, aircraft, series, species.
- •Latin/Greek origins: analysis → analyses, crisis → crises, phenomenon → phenomena.
- •-f/-fe to -ves: knife → knives, wife → wives, leaf → leaves.
How to Form Irregular Plural Nouns
Affirmative (+)
Learn each irregular form individually
Negative (-)
Same irregular forms in negative sentences
Question (?)
Same irregular forms in questions
💡 Some words have two acceptable plurals: fish/fishes, indexes/indices.
Examples of Irregular Plural Nouns
✓The children are playing.
✗The childs are playing.
Child → children (irregular).
✓I saw three deer.
✗I saw three deers.
Deer is the same singular and plural.
✓She has two teeth missing.
✗She has two tooths missing.
Tooth → teeth (vowel change).
Common Mistakes with Irregular Plural Nouns
💡 Practice Tips for Irregular Plural Nouns
- • Memorize common irregular plurals in groups (vowel changes, -en, same form).
- • -f/-fe usually becomes -ves: knife/knives, life/lives, wife/wives.
- • Same form: sheep, fish, deer, aircraft, series.
- • Latin/Greek: -is → -es (crisis/crises), -on → -a (phenomenon/phenomena).
Quick Quiz
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