1. Words ending in -O

Use ending -es if a noun ends in -o.

• Examples: potato - potatoes, tomato - tomatoes.

But: add only -s to words of foreign origin or abbreviated words ending in -o.

• Examples: piano - pianos (short from fortepiano), photo - photos (short from photograph)

2. Words ending in -Y

If a noun ends in -y that is preceded by a consonant, change the -y to -i and add -es.

• Examples: baby - babies, story - stories.

But: if -y follows a vowel, just add -s.

• Examples: day - days, boy - boys.

3. Words ending in -F or -FE

Some nouns that end in -f or -fe change the -f or -fe to -v and add -es.

• Examples: knife - knives, wolf - wolves

But: some other nouns ending in -f or -fe just add -s.

• Remember: handkerchief - handkerchiefs, safe - safes, cliff - cliffs.

4. Irregular Plural Nouns

Names of some creatures do not change their forms in plural.

Remember plural forms of the following words:

fish - fish

deer - deer

sheep - sheep