.以不可数名词结尾的复合名词无复数形式.
如：homework,newspaper等.
2.以man或woman为前缀的名词变复数时,前后两个名词都变成复数.
如：woman doctor→women doctors,man waiter→men waiters.
3.以两个名词构成的复合名词(前面的名词为man或woman除外),一般把后面的名词变复数.
如：boy friend→boy friends,paper bag→paper bags.
4.以“可数名词+介词(短语)”构成的复合名词变复数时,把前面名词变复数.
如：father-in-law→fathers-in-law.
5.以“动词 / 过去分词+副词”构成的复合名词变复数时,在词尾加s.
如：grown-up→grown-ups,stand-by→stand-bys.
6 以“man” "woman"等构成的复数名词,两个都要变复数
man doctor →men doctors
woman teacher →women teachers