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.

SINGULAR

James
loss
bush
bench
fox

PLURAL

Jameses
losses
bushes
benches
foxes

Examples 1

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

1. towel
5. shirt

2. torch
6. wish

3. box
7. waltz

4. guess
8. isthmus

Solutions

1. towels (regular)
3. boxes (ends in x)
5. shirts (regular)
7. waltzes (ends in z)

2. torches (ends in ch)
4. guesses (ends in ss)
6. wishes (ends in sh)
8. isthmuses (ends in s)

Nouns Ending in y

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

SINGULAR

way
key
boy
guy
tray

PLURAL

ways
keys
boys
guys
trays

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

SINGULAR

spy
baby
*Danny
tributary
candy

PLURAL

spies
babies
*Dannys (I know two Dannys)
tributaries
candies

Examples 2

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

1. strait
5. lagoon

2. bay
6. wish

3. lagoon
7. waltz

4. supply
8. isthmus

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.

SINGULAR

cuff
gulf
safe
cliff
roof

PLURAL

cuffs
gulfs
safes
cliffs
roofs 

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

SINGULAR

life
calf
wolf
knife
wife

PLURAL

lives
calves
wolves
knives
wives

Examples 3

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

1. puff
5. waif

2. half
6. leaf

3. cliff
7. roof

4. thief
8. sheaf

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.

SINGULAR

archipelago
auto
solo
piano
alto

PLURAL

archipelagos
autos
solos
pianos
altos

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

SINGULAR

echo
hero
veto
tomato
potato

PLURAL

echoes
heroes
vetoes
tomatoes
potatoes

Examples 4

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

1. piano
5. tangelo

2. hero
6. piccolo

3. solo
7. potato

4. echo
8. virtuoso

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.

SINGULAR

woman
man
person
tooth
foot

PLURAL

women
men
people
teeth
feet

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

SINGULAR

moose
deer
cod
sheep
trout

PLURAL

moose
deer
cod
sheep
trout

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.

1. mouse
5. goose

2. ox
6. woman

3. child
7. salmon

4. sheep
8. gentleman

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)