I. 名词复数规则变化 （非常重要）
1. 规则变化是在单数名词后加 s
如﹕cat – cats, fruit – fruits, apple – apples, pear – pears
2. 以子音字母加y结尾的，改y为i, 再加es, 但当y前面是元音时，y不变，直接加s
如﹕fly – flies, monkey – monkeys.
3. 以子音字母加o结尾的，一般加es
如﹕hero – heroes, tomato – tomatoes, potato – potatoes
4. 元音字母加o结尾的，只加s
如﹕bamboo – bamboos, kangaroo- kangaroos.
5. 某些外来语和简略语只加s
如：piano – pianos, photo – photos,
6. 一般以f或fe结尾的，变f或fe为ves
如﹕leaf – leaves, knife – knives, wife – wives, life – lives
7. 以s, ss, x, z, sh, ch结尾的，加es（但也有直接加s的）
如﹕glass – glasses, buzz – buzzes, dish – dishes, bench – benches, bus – buses, stomach – stomachs, box – boxes
归纳总结
| 变化类型 | Example |
| 1. 直接在名词后加s | cat – cats, fruit – fruits, apple – apples, pear – pears |
| 2. 以子音字母加y结尾的，改y为i, 再加es, 但当y前面是元音时，y不变， 直接加s, | fly – flies, monkey – monkeys. |
| 3. 以子音字母加o结尾的，一般加es, | hero – heroes, tomato – tomatoes, potato – potatoes |
| 4. 元音字母加o结尾的，只加s | bamboo – bamboos, kangaroo- kangaroos |
| 5. 某些外来语和简略语只加s | piano – pianos, photo – photos, |
| 6. 以f或fe结尾的，变f或fe 为ves | leaf – leaves, knife – knives, wife – wives, life – lives |
| 7. 以s, ss, x, z, sh, ch结尾的，加S （但也有直接加s的） | glass – glasses, buzz – buzzes, dish – dishes, bench – benches, bus – buses, stomach – stomachs, box – boxes |
1.改变内部元音字母﹕foot – feet, tooth – teeth, man – men, woman – women, mouse – mice.
2.在字尾加en或ren，ox – oxen, child – children
3.单复数同形﹕sheep – sheep, deer – deer,
4.有些外来语保留原来的复数形式﹕bacterium – bacteria, phenomenon – phenomena
| 变化类型 | Example |
| 改变内部元音字母 | foot – feet, tooth – teeth, man – men, woman – women, mouse – mice. |
| 在字尾加en或ren | ox – oxen, child – children |
| 单复数同形 | sheep – sheep, deer – deer, fish, fish |
| 有些外来语保留原来的复数形式 | bacterium – bacteria, (细菌) phenomenon – phenomena（现象） |
