As you know, in English you generally make a word pluralby adding an ‘s’ at the end. There seems to be some confusion, though, about how to make plurals of terms made up of more than one word. For example, do you say bicycles shops or bicycle shops? Do you say power of attorneys or powers of attorney?
众所周知，在英语中要把一个名词变成复数，只要在这个词的后面加上“s”就行了。不过，当一个名词变成了由几个名词组成的词组时，就让人摸不着头脑了。举个例子，如果你要表示自行车商店的复数形式，你是用“bicycles shop”还是“bicycle shops”?在表示授权书的复数时，你是说“power of attorneys”还是“powers of attorney”?
The answers are bicycle shops and powers of attorney.
正确的说法是“bicycle shops”和“powers of attorney”。
The rule is that you pluralise the “head” of the term.
名词词组复数变化的规则就是：变“重点词”。
The term bicycle shop is typical of most noun groups. The “head” is the last word in the group. The previous word or words act as an adjective. So the last word in the group is pluralised. Here are some more examples:
“自行车商店”这个名词词组是一个很典型的例子。在这个词组中，重点词是最后一个词，即商店(shop);前面的词或者词组只是起到了一个形容词的修饰作用而已。因此，在这个词组中，最后一个词变成了复数形式。更多类似的例子：
Bank account => Bank accounts
银行账户
Company car => Company cars
公司用车
Price limit => Price limits
价格限制
Termination notice => Termination notices
终止通知
Service charge payment => Service charge payments
服务费收费
Employee share optionscheme => Employee share option schemes
雇员股份认购权计划
However, a term like power of attorney acts rather differently. Power is the “head” and of attorney is an adjectival phrase which describes the “head”. Here are some other examples of terms that behave in the same way:
然而，像授权书这样的词组就又是另外一番解释了。在这个词组中，重点词是权利(power)，律师(attorney)一词只是用来充当形容词的修饰成分。更多类似的例子：
Article of association => Articlesof association
公司章程
Code of conduct => Codesof conduct
行为守则
Conflict of interest => Conflictsof interest
利益冲突
Course of action => Coursesof action
行动步骤
Notary public => Notariespublic
公证人
Statement of claim => Statementsof claim
起诉书
以上就是托福写作中常用到的词组复数形式，正确的表达是拿到托福写作高分的重要手段之一。大家好好练习吧！天道留学预祝大家取得理想成绩