Plural nouns name more than one person, place, thing, or idea. In English, most plurals are formed by adding an ending to the singular form. Some nouns change spelling in special ways, and some keep the same form in singular and plural.

For most nouns, make the plural by adding -s to the singular. This includes many nouns ending in vowels and many nouns ending in most consonants. The spelling usually stays the same; you simply add the plural ending.

Word/Phrase	Definition	Example
-s	➤ Add -s to the singular noun	➤ book → books
-s	➤ Works with most nouns ending in a vowel	➤ key → keys
-s	➤ Works with many nouns ending in common consonants	➤ car → cars

Add -es when a noun ends in sounds that already hiss or buzz, so an extra syllable is needed. This commonly happens with nouns ending in -s, -ss, -sh, -ch, -x, and -z. The plural is pronounced with an extra sound, like a new syllable at the end.

Rule	Example
Nouns ending in -s or -ss add -es	bus → buses
Nouns ending in -sh add -es	dish → dishes
Nouns ending in -ch add -es	match → matches
Nouns ending in -x add -es	box → boxes
Many nouns ending in -z add -es	quiz → quizzes

If a noun ends in a consonant + y, change y to i and add -es. If a noun ends in a vowel + y, keep y and add -s. This rule is about spelling patterns, not just the final letter.

Rule	Example
Consonant + y: y → ies	city → cities
Consonant + y: y → ies	baby → babies
Vowel + y: keep y, add -s	toy → toys
Vowel + y: keep y, add -s	day → days

Some nouns ending in -f or -fe form the plural by changing the ending to -ves. Other nouns ending in -f simply add -s, so this pattern has important exceptions. The safest approach is to learn the common -ves nouns as a group.

Word/Phrase	Definition	Example
-f or -fe → -ves	➤ Change ending to -ves for many common nouns	➤ knife → knives
-f or -fe → -ves	➤ Common pattern in everyday vocabulary	➤ leaf → leaves
-f or -fe → -ves	➤ Common pattern in family words	➤ wife → wives
-f + -s	➤ Some nouns keep f and just add -s	➤ roof → roofs

Nouns ending in -o can take -s or -es depending on the word. Many everyday words add -es, while many newer or shortened words add -s. Because there is variation, learning the plural together with the noun is often helpful.

Rule	Example
Some -o nouns add -es	potato → potatoes
Some -o nouns add -es	hero → heroes
Many -o nouns add -s	photo → photos
Many -o nouns add -s	piano → pianos

Some irregular plurals change a vowel or other internal spelling instead of adding a regular ending. These forms come from older patterns in English and must be memorized. They are common, especially for people and animals.

Word/Phrase	Definition	Example
man → men	➤ Vowel changes in the plural	➤ The men are here.
woman → women	➤ Vowel changes in the plural	➤ The women are ready.
foot → feet	➤ Vowel changes in the plural	➤ My feet hurt.
tooth → teeth	➤ Vowel changes in the plural	➤ Brush your teeth.
mouse → mice	➤ Vowel changes in the plural	➤ Mice are small.

A small group of nouns form plurals with special endings, often from Latin or Greek. These are frequent in academic or formal contexts, and some have both a traditional plural and a more regular plural. In careful writing, the traditional plural is often preferred.

Word/Phrase	Definition	Example
child → children	➤ Irregular plural ending -ren	➤ The children are playing.
person → people	➤ Irregular plural form	➤ Many people agree.
cactus → cacti	➤ Latin plural -i	➤ Cacti grow in deserts.
analysis → analyses	➤ Greek plural -es for -is nouns	➤ Two analyses were published.
criterion → criteria	➤ Greek plural -a for -on nouns	➤ The criteria are strict.

Some nouns have the same form in singular and plural. Many of these are animals or nouns used as mass-like categories, and the plural meaning is shown by context or by a number word. In these cases, the noun form stays unchanged even when it refers to more than one.

Word/Phrase	Definition	Example
sheep → sheep	➤ Same form for singular and plural	➤ one sheep, two sheep
deer → deer	➤ Same form for singular and plural	➤ three deer
fish → fish	➤ Often same form, especially as food or a group	➤ We saw many fish.
aircraft → aircraft	➤ Same form in singular and plural	➤ two aircraft

The plural ending is spelled -s or -es, but it has three common pronunciations. The sound depends on the final sound of the singular noun, not the final letter. Learning these patterns helps you speak clearly and choose -s versus -es more confidently.

Rule	Description	Notation	Example
After voiceless sounds	➤ Plural ending sounds like s	➤ /s/	➤ cat → cats
After voiced sounds	➤ Plural ending sounds like z	➤ /z/	➤ dog → dogs
After sibilant sounds	➤ Add an extra syllable; ending sounds like iz	➤ /ɪz/	➤ bus → buses

To form plurals accurately, first try the regular rules: -s for most nouns, -es for hissing endings, and the y rule. Then check for common special spelling patterns like -f to -ves and -o endings. If the word is irregular or has no change, treat its plural as a vocabulary item to learn with the noun.