1.直接加s：lesson—lessons,pen —pens,等.
2.以s,x,ch,sh 结尾的加es：bus—buses,box—boxes,等.
3.以“辅音字母 +y”结尾的,变y为i,再加es：baby—babies,country —countries,等.但是,“元音字母+y”结尾的,则是直接加s：boy—boys,等.
4.以f或fe结尾的,一般将f或fe改为v,再加es：knife—knives,leaf—leaves,等.
5.以字母o结尾的词加es或s：photo—photos,tomato—tomatoes,等.
6.不规则变化.如：
a.特殊的复数形式：child—children,mouse—mice,等.
b.变oo为ee：foot—feet,tooth —teeth,等.
c.含有man 或woman词语的复数是将a改为e：man—men,Frenchman—Frenchmen,等.如果man或woman作另一名词的定语时,和所修饰的名词一起变为复数：man driver—men drivers,woman doctor—women doctors,等.
d.单复数形式相同：sheep,deer,Japanese等.
考例再现:
1．Last night,there was a food accident.Ten _______ were ill,but no _______ were lost.
A.child; lives B.children; life C.children; lives D.child; life (C)
2．The boy always brushes his _____ before he goes to bed.
3．The Japanese _____ will not leave China until she finishes her study.
A.woman B.women C.man D.men (A)
解析:从“she”可推测出前面为单数、女性,故选A.
4．Can you see nine ________ in the picture?
A.sheep B.dog C.pig D.horse (A)