1.中间没有连字符的合成名词在词尾变复数：
bookshelf→bookshelves handful→handfuls
2.man和 woman构成的复合名词，二者均变为复数。
man servant→men servants
woman teacher→women teachers
3.中间有连字符的合成次，在主体词(中心意义的词)末尾变复数：
sister-in-law→sisters-in-law
looker-on→lookers-on
editor-in-chief→editors-in-chief
4.下列合成名词在后一个词上变化：
sit-in→sit-ins, grown-up→grown-ups
stand-by→stand-bys touch-me-not→touch-me-nots
go-between→go-betweens
