Irregular Plural Nouns

Some nouns have irregular plural forms. We must learn these irregular plural nouns if we do not know them already.

Nouns Ending in s, sh, ch, x, or z

We add es to a singular noun ending in the following letters: s, sh, ch, x, z.

Examples 1

For 1-8, write the plural form of each singular noun.

Solutions

Nouns Ending in y

We add an s when a singular noun ends with ay, ey, oy, or uy.

We change y to i and add es when a singular noun ends in a consonant plus y, unless it is someone's name.

Examples 2

For 1-8, write the plural form of each singular noun.

Solutions

We show correct spelling of irregular plural nouns:

1. straits (regular)
2. bays (ends in ay)
3. lagoons (regular)
4. supplies (ends in consonant plus y)
5. alleys (ends in ey)
6. toys (ends in oy)
7. guys (ends in uy)
8. skies (ends in consonant plus y)

Nouns Ending in f, ff, and fe

For most nouns ending in f, ff, and fe, we add s to form the plural.

However, for some nouns ending in f and fe, we change the f to v and add es. See the following irregular plural nouns:

Examples 3

Write the plural form of each singular noun. Use the dictionary if you are unsure.

Solutions

We show the correct spelling of irregular plural nouns.

1. puffs (word ending in ff )
2. We check the dictionary and find that the plural of half is halves.
3. cliffs (word ending in ff )
4. We check the dictionary and find that the plural of thief is thieves.
5. waifs (word ending in f)
6. We check the dictionary and find that the plural of leaf is leaves.
7. roofs (word ending in f)
8. We check the dictionary and find that the plural of sheaf is sheaves.

Nouns Ending in o

We usually add s to form the plurals of nouns ending in o, especially if they are musical terms.

However, the following illustrate the rule that nouns ending in -o preceded by a consonent add -es to form the plural:

Examples 4

Write the plural form of each singular noun. Use the dictionary if you are unsure.

Solutions

1. pianos (musical term ending in o)
2. We notice that the word hero is in the list of exceptions to words ending in o. We check the dictionary and find that the plural of hero is heroes.
3. solos (musical term ending in o)
4. We notice that the word echo is in the list of exceptions to words ending in o. We check the dictionary and find that the plural of echo is echoes.
5. tangelos (We check the dictionary and find that the plural of tangelo is not irregular, so we just add an s.)
6. piccolos (musical term)
7. potatoes (We check the dictionary and find that the plural of potato is potatoes.)
8. virtuosos (musical term)

Unchanging Irregular Plural Nouns

Some singular nouns change completely in their plural forms.

Other nouns are the same in their singular and plural forms.

Dictionary

When we are uncertain, we use a dictionary to check plural forms. If the plural form of the noun is regular (only add s to the singular noun), then the dictionary will not list it. Sometimes, the dictionary will list two plural forms for a noun. The first one listed is the preferred one. (Example: cactus n., pl. cacti, cactuses)

Examples 5

Write the plural form of each of the following singular nouns. Use a dictionary if you are in doubt.

Solutions

We show the correct spelling of irregular plural nouns.

1. mice (irregular form)
2. oxen (irregular form)
3. children (irregular form)
4. We check the dictionary and find that the plural of sheep is sheep.
5. geese (irregular form)
6. women (irregular form)
7. We check the dictionary and find that the plural of salmon is salmon.
8. gentlemen (irregular form)