Most English plurals are formed quite simply. Just add -s to the end of a noun:
- dog → dogs
- building → buildings
However, if the noun ends in -s, -ss, -z, -x, -ch, or -sh, add -es to form the plural:
- boss → bosses
- box → boxes
- witch → witches
- dish → dishes
If the noun ends in a consonant plus -y, change the -y to -i, then
add -es:
- lady → ladies
- penny → pennies
Words that end in -o are a special problem. Some form their plural by adding -s, and others form their plural by adding -es. Look at these examples:
| Singular | Plural + -s | Singular | Plural + -es |
| auto | autos | potato | potatoes |
| piano | pianos | hero | heroes |
| alto | altos | echo | echoes |
| zoo | zoos | veto | vetoes |
| solo | solos | cargo | cargoes |
Consult a dictionary to know precisely which plural ending to use with words that end in -o.
There are a few words that form the plural with an -s ending but also require a consonant change in which f changes to v:
- knife → knives
- leaf → leaves
- shelf → shelves
- wife → wives
- wolf → wolves
Certain other nouns form their plural in completely irregular ways. Fortunately, the list is quite brief:
- child → children
- mouse → mice
- foot → feet
- person → people (or persons)
- goose → geese
- deer → deer [no change!]
- man → men
- woman → women
- tooth → teeth
- ox → oxen