Nouns can be singular (one) or plural (more than one).

To make a noun plural, we usually change its ending. But there are many different rules depending on the word.

1. Regular Plural Nouns (just add -s)

Most nouns become plural by simply adding -s.

• book → books

• computer → computers

• teacher → teachers

• car → cars

2. Nouns ending in -s, -sh, -ch, -x, -z (add -es)

When a noun ends with these sounds, we add -es to make it easier to pronounce.

• box → boxes

• bush → bushes

• church → churches

• watch → watches

• fox → foxes

3. Nouns ending in -y

• If a noun ends in consonant + y, change y → i and add -es.

  • city → cities

  • story → stories

  • party → parties

  • baby → babies

• If a noun ends in vowel + y, just add -s.

  • key → keys

  • toy → toys

4. Nouns ending in -f or -fe

The rule for nouns ending in -f or -fe is:

👉 Often, the f changes to v and then we add -es.

• wife → wives

• knife → knives

• leaf → leaves

But ⚠️ not all words follow this pattern. Some just take -s without changing f to v.

• roof → roofs (not rooves)

• cliff → cliffs

• chief → chiefs

5. Nouns ending in -o

• Some take -es:

  • tomato → tomatoes,

  • hero → heroes,

  • echo → echoes,

  • tornado → tornadoes

  • potato → potatoes,

• Some just take -s:

  • photo → photos,

  • piano → pianos,

  • zero → zeros/may also be zeroes (both are used)

    
    

• Some can take both forms:

  • volcano → volcanoes / volcanos

    
    

6. Irregular Plurals

Some nouns don’t follow the rules.

• man → men

• woman → women

• child → children

• foot → feet

• tooth → teeth

• mouse → mice

7. Nouns that stay the same in plural

Some nouns don’t change at all.

• deer → deer

• buffalo → buffalo (also buffalos is correct)

• cargo → cargo or cargoes

• sheep → sheep

8. Special Cases & Notes

• Words ending in -us, -is, -on (from Latin/Greek) often change differently at higher levels (not much needed now but examples: cactus → cacti, analysis → analyses, phenomenon → phenomena).