| (a) | ||
| potato, potatoes | hero, heroes | mulatto, mulattoes |
| tomato, tomatoes | buffalo, buffaloes | cargo, cargoes |
| negro, negroes | echo, echoes | motto, mottoes |
| (b) | ||
| solo, solos | piano, pianos | memento, mementos |
| halo, halos | lasso, lassos | canto, cantos |
| zero, zeros | quarto, quartos | soprano, sopranos |
| stilletto, stillettos | ||
The older English words ending in o form the plural by adding es, as in potatoes; those more recently taken into the language form the plural by adding s, as in quartos.
Exercise 32—Nouns in f and fe
| leaf, leaves | calf, calves | wife, wives |
| loaf, loaves | sheaf, sheaves | shelf, shelves |
| half, halves | wolf, wolves | elf, elves |
| life, lives | beef, beeves | wharf, wharves (or wharfs) |
| self, selves | knife, knives |
With the exception of the words given above, nouns ending in an f sound form the plural in the regular way; as,
| hoof, hoofs | scarf, scarfs | beliefs, beliefs |
| chief, chiefs | reef, reefs | grief, griefs |
Exercise 33—Irregular Plurals
Some nouns form their plural by a change of vowel; as,
| man | men | foot | feet |
| woman | women | tooth | teeth |
| goose | geese | mouse | mice |
A few words retain the old time plural en; as,