3、以下名词单复数同形：
means headquarters
works species
aircraft Chinese headquarters
works species
aircraft Chinese
sheep fish
中国的计量单位：li, yuan, mu等
实例：
Every means has been tried out, but without satisfactory results.
4、形式上是复数的学科名称，如physics , statistics, dynamics 作单数看待;时间、距离、钞票、重量等复数，可以看作一个整体作单数处理，如：Two days is not enough for me to finish thetask.
5、名词做另一名词的修饰语：
一般用单数形式，如：a college student中的college 为单数形式。
注意：
以下名词做另一名词修饰语时要用复数形式：sport a sportsman / sale a sales department / savings a savings account / communication
a communications satellite / greeting a greetings cable
不规则名词修饰另一名词时数的变化：a woman doctor two women doctors / the Chinese womens volleyball team / a children hospital
6、family, group, police，committee, team, box, audience等词，可以是单数，也可以是复数，关键要看题目所给的提示，例如：
The whole box of matches _____ wet; I couldnt light a simple one
A. was
B. is
C. were
D. are
解题思路：这道题如果没有后半句I couldnt light a simple one，是没办法解答的。这句话提示了两点：
时态为过去时，故B、D已不可能了;
a simple one说明是指盒子内的一根根火柴，故答案为C.试想，如果我们把后半句改为 I had to throw it away, 那么正确答案应是A.
所以，看清题目的提示对于解题是非常重要的。