Most singular nouns form the plural by adding -s.
| Singular | Plural |
|---|---|
| boat | boats |
| house | houses |
| cat | cats |
| river | rivers |
A singular noun ending in s, x, z, ch, sh makes the plural by adding-es.
| Singular | Plural |
|---|---|
| bus | buses |
| wish | wishes |
| pitch | pitches |
| box | boxes |
A singular noun ending in a consonant and then y makes the plural by dropping the y and adding-ies.
| Singular | Plural |
|---|---|
| penny | pennies |
| spy | spies |
| baby | babies |
| city | cities |
| daisy | daisies |
There are some irregular noun plurals. The most common ones are listed below.
| Singular | Plural |
|---|---|
| woman | women |
| man | men |
| child | children |
| tooth | teeth |
| foot | feet |
| person | people |
| leaf | leaves |
| mouse | mice |
| goose | geese |
| half | halves |
| knife | knives |
| wife | wives |
| life | lives |
| elf | elves |
| loaf | loaves |
| potato | potatoes |
| tomato | tomatoes |
| cactus | cacti |
| focus | foci |
| fungus | fungi |
| nucleus | nuclei |
| syllabus | syllabi/syllabuses |
| analysis | analyses |
| diagnosis | diagnoses |
| oasis | oases |
| thesis | theses |
| crisis | crises |
| phenomenon | phenomena |
| criterion | criteria |
| datum | data |
Some nouns have the same form in the singular and the plural.
| Singular | Plural |
|---|---|
| sheep | sheep |
| fish | fish |
| deer | deer |
| species | species |
| aircraft | aircraft |
