Irregular Plurals | English Grammar Guide for French Students

• 1 Do not follow the regular -s or -es pattern
• 2 Often have historical or linguistic origins
• 3 Include many common, frequently used words
• 4 Must be learned individually

1 Many irregular plurals change their internal vowel sound
2 These often derive from Old English
3 The vowel changes from singular to plural
4 Examples: man → men, foot → feet, tooth → teeth

• 1 man → men
• 2 woman → women
• 3 foot → feet
• 4 tooth → teeth
• 5 goose → geese
• 6 mouse → mice
• 7 louse → lice
• 8 ox → oxen

1 Some nouns have identical singular and plural forms
2 The context indicates whether the word is singular or plural
3 These often refer to animals
4 Examples: sheep, deer, fish, species

• 1 sheep → sheep (one sheep, two sheep)
• 2 deer → deer (one deer, many deer)
• 3 fish → fish (one fish, many fish)
• 4 species → species (one species, many species)
• 5 series → series (one series, many series)
• 6 aircraft → aircraft (one aircraft, two aircraft)

1 Many academic, scientific, and medical terms retain their original plural forms
2 Latin words often end in -us (plural -i) or -um (plural -a)
3 Greek words often end in -on (plural -a) or -is (plural -es)
4 These are common in formal and professional contexts

1 Latin -us to -i: focus → foci, nucleus → nuclei, stimulus → stimuli
2 Latin -um to -a: datum → data, medium → media, curriculum → curricula
3 Greek -on to -a: phenomenon → phenomena, criterion → criteria
4 Greek -is to -es: analysis → analyses, crisis → crises, thesis → theses

1 Some words retain archaic plural forms
2 These often relate to body parts, clothing, or traditional concepts
3 Some have both traditional and modern plural forms
4 Examples: children, brethren, oxen

• 1 child → children
• 2 brother → brethren (formal) or brothers (modern)
• 3 person → people
• 4 mouse → mice
• 5 die → dice

1 Some words have both traditional irregular and regular plural forms
2 brother: brothers (modern) or brethren (formal/archaic)
3 formula: formulas (modern) or formulae (traditional)
4 index: indexes (modern) or indices (formal)
5 Context and formality determine which is preferred

1 Passerby: passersby (the modifier changes, not the head word)
2 Commander in chief: commanders in chief
3 Man of war: men of war
4 The main noun determines the plural form

• 1 Applying regular rules to irregular nouns: "childs" instead of "children"
• 2 Forgetting vowel changes: "foots" instead of "feet"
• 3 Adding -s to unchanged plurals: "sheeps" instead of "sheep"
• 4 Confusing similar-looking irregular forms

1 ✓ Correct: "children"
2 ✗ Incorrect: "childs"
3 ✓ Correct: "feet"
4 ✗ Incorrect: "foots"

1. man → _______

2. woman → _______

3. tooth → _______

4. foot → _______

5. mouse → _______

6. goose → _______

7. sheep → _______

8. deer → _______

9. person → _______

10. child → _______

1. men

2. women

3. teeth

4. feet

5. mice

6. geese

7. sheep

8. deer

9. people

10. children

1 English: Has both regular and irregular plural forms
2 French: Also has irregular plurals but different patterns
3 English: More varied irregular patterns
4 French: Often adds -s or -x to form plurals

• 1 English irregular plurals require more memorization than French
• 2 Many common English words have irregular plurals
• 3 Focus on the most frequently used irregular plurals
• 4 Pay attention to pronunciation differences

1 Vowel change group: man-men, foot-feet, tooth-teeth (same pattern)
2 Same form group: sheep-sheep, deer-deer, fish-fish (no change)
3 Completely different: child-children, person-people
4 Create sentences: "The man with his teeth went to feed the mice"

• 1 Practice with the most common irregular plurals first
• 2 Use flashcards to memorize pairs
• 3 Read English texts to see natural usage patterns
• 4 Focus on pronunciation differences between singular and plural

• Vowel changes: man → men, foot → feet, tooth → teeth
• No change: sheep → sheep, deer → deer, fish → fish
• Completely different: child → children, person → people
• Latin/Greek origins: criterion → criteria, phenomenon → phenomena
• Historical forms: ox → oxen, brother → brethren

Remember: Most common English words have irregular plurals!

• Start with the most frequent irregular plurals
• Group similar patterns together
• Practice regularly to build muscle memory