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	🇨🇳 中文 词/短语	Definition	🇨🇳 中文 定义	Example	🇨🇳 中文 示例
-s	➕ -s	➤ Add -s to the singular noun	➤ 将 -s 添加到单数名词	➤ book → books	➤ book → books
-s	➕ -s	➤ Works with most nouns ending in a vowel	➤ 适用于大多数以元音结尾的名词	➤ key → keys	➤ key → keys
-s	➕ -s	➤ Works with many nouns ending in common consonants	➤ 适用于许多以常见辅音结尾的名词	➤ car → cars	➤ 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	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Nouns ending in -s or -ss add -es	🧩 以 -s 或 -ss 结尾的名词加 -es	bus → buses	🗣️ bus → buses
Nouns ending in -sh add -es	🧩 以 -sh 结尾的名词加 -es	dish → dishes	🗣️ dish → dishes
Nouns ending in -ch add -es	🧩 以 -ch 结尾的名词加 -es	match → matches	🗣️ match → matches
Nouns ending in -x add -es	🧩 以 -x 结尾的名词加 -es	box → boxes	🗣️ box → boxes
Many nouns ending in -z add -es	🧩 以 -z 结尾的多数名词加 -es	quiz → quizzes	🗣️ 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	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Consonant + y: y → ies	🔤 辅音 + y: y → ies	city → cities	🗣️ city → cities
Consonant + y: y → ies	🔤 辅音 + y: y → ies	baby → babies	🗣️ baby → babies
Vowel + y: keep y, add -s	🔤 元音 + y: 保留 y，加 -s	toy → toys	🗣️ toy → toys
Vowel + y: keep y, add -s	🔤 元音 + y: 保留 y，加 -s	day → days	🗣️ 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	🇨🇳 中文 词/短语	Definition	🇨🇳 中文 定义	Example	🇨🇳 中文 示例
-f or -fe → -ves	📝 -f or -fe → -ves	➤ Change ending to -ves for many common nouns	➤ 将结尾改为 -ves 对于许多常见名词	➤ knife → knives	➤ knife → knives
-f or -fe → -ves	📝 -f or -fe → -ves	➤ Common pattern in everyday vocabulary	➤ 日常词汇中的常见模式	➤ leaf → leaves	➤ leaf → leaves
-f or -fe → -ves	📝 -f or -fe → -ves	➤ Common pattern in family words	➤ 家庭词中的常见模式	➤ wife → wives	➤ wife → wives
-f + -s	⚠️ -f + -s	➤ Some nouns keep f and just add -s	➤ 某些名词保持 f 仅加 -s	➤ roof → roofs	➤ 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	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Some -o nouns add -es	🔤 某些 -o 名词加 -es	potato → potatoes	🗣️ potato → potatoes
Some -o nouns add -es	🔤 某些 -o 名词加 -es	hero → heroes	🗣️ hero → heroes
Many -o nouns add -s	🔤 许多 -o 名词加 -s	photo → photos	🗣️ photo → photos
Many -o nouns add -s	🔤 许多 -o 名词加 -s	piano → pianos	🗣️ 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	🇨🇳 中文 词/短语	Definition	🇨🇳 中文 定义	Example	🇨🇳 中文 示例
man → men	🧠 man → men	➤ Vowel changes in the plural	➤ 复数中的元音变化	➤ The men are here.	➤ The men are here.
woman → women	🧠 woman → women	➤ Vowel changes in the plural	➤ 复数中的元音变化	➤ The women are ready.	➤ The women are ready.
foot → feet	🧠 foot → feet	➤ Vowel changes in the plural	➤ 复数中的元音变化	➤ My feet hurt.	➤ My feet hurt.
tooth → teeth	🧠 tooth → teeth	➤ Vowel changes in the plural	➤ 复数中的元音变化	➤ Brush your teeth.	➤ Brush your teeth.
mouse → mice	🧠 mouse → mice	➤ Vowel changes in the plural	➤ 复数中的元音变化	➤ Mice are small.	➤ 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	🇨🇳 中文 词/短语	Definition	🇨🇳 中文 定义	Example	🇨🇳 中文 示例
child → children	📚 child → children	➤ Irregular plural ending -ren	➤ 不规则复数结尾 -ren	➤ The children are playing.	➤ The children are playing.
person → people	📚 person → people	➤ Irregular plural form	➤ 不规则复数形式	➤ Many people agree.	➤ Many people agree.
cactus → cacti	📚 cactus → cacti	➤ Latin plural -i	➤ 拉丁语复数 -i	➤ Cacti grow in deserts.	➤ Cacti grow in deserts.
analysis → analyses	📚 analysis → analyses	➤ Greek plural -es for -is nouns	➤ 对 -is 名词的希腊语复数 -es	➤ Two analyses were published.	➤ Two analyses were published.
criterion → criteria	📚 criterion → criteria	➤ Greek plural -a for -on nouns	➤ 对 -on 名词的希腊语复数 -a	➤ The criteria are strict.	➤ 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	🇨🇳 中文 词/短语	Definition	🇨🇳 中文 定义	Example	🇨🇳 中文 示例
sheep → sheep	🟰 sheep → sheep	➤ Same form for singular and plural	➤ 单数与复数同形	➤ one sheep, two sheep	➤ one sheep, two sheep
deer → deer	🟰 deer → deer	➤ Same form for singular and plural	➤ 单数与复数同形	➤ three deer	➤ three deer
fish → fish	🟰 fish → fish	➤ Often same form, especially as food or a group	➤ 常同形，尤其作为食物或一个群体	➤ We saw many fish.	➤ We saw many fish.
aircraft → aircraft	🟰 aircraft → aircraft	➤ Same form in singular and plural	➤ 单数与复数同形	➤ two aircraft	➤ 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	🇨🇳 中文 规则	Description	🇨🇳 中文 描述	Notation	🇨🇳 中文 表示法	Example	🇨🇳 中文 示例
After voiceless sounds	🔊 无声音后	➤ Plural ending sounds like s	➤ 复数结尾发音像 s	➤ /s/	➤ /s/	➤ cat → cats	➤ cat → cats
After voiced sounds	🔊 有声音后	➤ Plural ending sounds like z	➤ 复数结尾发音像 z	➤ /z/	➤ /z/	➤ dog → dogs	➤ dog → dogs
After sibilant sounds	🔊 叹音后	➤ Add an extra syllable; ending sounds like iz	➤ 增加一个音节；结尾发音像 iz	➤ /ɪz/	➤ /ɪz/	➤ bus → buses	➤ 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.