3.辅音字母 + y结尾的变y为i,再加es: cities,countries, parties,factories

　　4.以o结尾的词多数+es heroes Negroes potatoes tomatoes

　　zeroes / zeros

　　以 o 结尾并且词尾有两个元音字母 +s radios, zoos, bamboos , (pianos ,kilos photos是特殊)

　　5.以f, fe 结尾的改f,或fe为v,再+es,例如:leaves, lives, wives knives, halves, wolves

　　The thief’s wife killed three wolves with some leaves and knives in half of her life.

　　但是,也有一些+s,如roofs, proofs, gulfs, beliefs,

　　handkerchiefs / handkerchieves

　　Ⅱ: 不规则的可数名词变复数的规则：

　　1. man—men, woman—women, tooth—teeth, foot—feet,

　　child—children, mouse—mice,

　　2.单复数相同: sheep, fish, deer, means, Chinese, Japanese,

　　fish如表示不同种类的鱼时复数是fishes;

　　There are many kinds of fishes in that lake.

　　3.以man, woman 修饰名词构成合成词时,两个词都变化.

　　man servant—men servants(男仆). (boy/girl students)

　　woman doctor—women doctors.

　　4.复合名词的复数形式:

　　son-in-law----sons-in-law (主体名词变化)

　　film-goer----film-goers, grown-up----grown-ups

　　(如果没有主体名词,在词尾加复数)

　　5.字母,阿拉伯数字的复数形式一般加“’s ”或“s”.

　　There are two l’s in the word “ all ”.

　　It happened in the 1960’s /1960s.

　　I will not accept your if’s and but’s.

　　6.物质名词一般没有复数，有时用复数形式表示不同种类，

　　wheats, fruits, vegetables,有时表示更广的词义，