一般情况加 -s

book → books

girl → girls

bag → bags

car → cars

以 s, sh, ch, x 等结尾加 -es

bus → buses

watch → watches

box → boxes

brush → brushes

以辅音字母 + y结尾，变 y 为 i 再加 -es

baby → babies

city → cities

country → countries

以 f 或 fe 结尾，多数变 f 或 fe 为 v 再加 -es

wife → wives

knife → knives

half → halves

thief → thieves

以 o 结尾，有些加 -es

Negroes → heroes

tomatoes → potatoes

photos → photos

不规则名词

foot → feet

goose → geese

tooth → teeth

child → children

man → men

woman → women

sheep → sheep

deer → deer

mouse → mice

某些外来词

datum → data

medium → media

bacterium → bacteria

curriculum → curricula

criterion → criteria

phenomenon → phenomena

复合名词

-manservant → menservants

woman student → women students

grown up → grown ups

brother in law → brothers in law

需要注意的是，人名的复数形式并不常见，通常用于表示“若干个叫…的人”或“像…一样的人”。例如：

There are two Marys and three Roberts in his class.

希望这些信息对你有所帮助!如果有更多具体的名词需要查询，请随时告诉我。