Plural Nouns

Rules, exceptions, and tips for naming multiple things

A plural noun names two or more people, places, things, or ideas. Most are formed by adding -s or -es, but English has many exceptions!

Key Characteristics

Plural vs. Singular:
  • Refers to multiples: "cats" (vs. "cat")
  • Takes plural verbs: "The dogs bark" (not "barks")
  • Uses plural determiners: "these," "many," "some"
  • No indefinite articles: "a/an" only with singulars

Regular Plural Rules

1. Add -s

Most common rule:
  • cat → cats
  • book → books
  • tree → trees

2. Add -es

For nouns ending in -s, -ss, -sh, -ch, -x, -z:
  • bus → buses
  • box → boxes
  • quiz → quizzes (double z + -es)

3. Change -y to -ies

When -y follows a consonant:
  • baby → babies
  • city → cities
  • Exception: boy → boys (-y after vowel)

4. Add -s or -es to -o endings

No consistent rule—must memorize:
  • photo → photos
  • potato → potatoes
  • hero → heroes

Irregular Plurals

1. Vowel Changes

Internal spelling changes:
  • foot → feet
  • tooth → teeth
  • mouse → mice

2. -en Endings

Rare but important:
  • child → children
  • ox → oxen

3. Same Singular and Plural

No change:
  • sheep → sheep
  • fish → fish (or fishes for species)
  • aircraft → aircraft

4. Foreign Plurals

From Latin/Greek:
  • cactus → cacti (or cactuses)
  • analysis → analyses
  • criterion → criteria

Special Cases

1. Uncountable Nouns

No plural form:
  • Incorrect: "informations," "furnitures"
  • Correct: "information," "furniture"

2. Collective Nouns

Singular form, plural meaning:
  • "The team are arguing" (British English)
  • "The staff have different opinions"

3. Compound Nouns

Pluralize the main word:
  • mother-in-law → mothers-in-law
  • passerby → passersby

Common Mistakes

Avoid these errors:
  • Apostrophes in plurals:
    ❌ "Banana's for sale"
    ✅ Bananas for sale
  • Incorrect irregular plurals:
    ❌ "Two childs"
    ✅ Two children
  • Uncountable nouns as plurals:
    ❌ "I need advices"
    ✅ I need advice

Practice Exercises

1. Form the Plurals

  • knife → knives
  • crisis → crises
  • tomato → tomatoes

2. Correct the Errors

  • ❌ "The datas are incorrect." → "The data is incorrect."
  • ❌ "I have three mouses." → "I have three mice."

3. Identify Regular vs. Irregular

  • dogs → regular
  • geese → irregular
  • wishes → regular