则What, who, which, any, more, all 等代词可以是单数，也可是复数， 主要靠意思来决定。Which is your bag? Which are your bags?

Are any of you good at English? Has any of you got a pen?

All can be done has been done. All is going well.

All have been taken out. All have gone to Beijing.

表示时间重量长度价值等的名词的复数作主语时，谓语动词通常用单数形式，这是由于作主语的名词在概念上是一个整体。Thirty minutes is enough for the work..

Twenty pounds is too dear.

如强调这类词的复数意义，则谓语动词要用复数形式

Forty kilos of water are used every day.

若英语是书名名格言剧名报名国名等的复数形式，其谓语动词通常用单数形式。The United States is smaller than China.

“The Arabian Nights” is an interesting story-book.

表数量的短语“one and a half”后面接复数名词作主语时，其谓语动词要用单数形式。One and a half apples is left on the table.

一些学科名词是以-ics结尾，如：mathematics, politics, physics 以及news, works 等。都属于形式上是复数的名词， 实际意义为单数名词，

它们作主语时，其谓语动词要用单数形式。The paper works was built in 1990.这家造纸厂建于1990年。

I don’t think physics is easy to study.

trousers, glasses, clothes, shoes, scissors (剪刀)等词作主语时，谓语用复数，但如果这些名词前有a(the) pair of 等量词修饰时(clothes被a suit of 修饰)谓语动词用单数。My glasses are broken.

The pair of shoes under the bed is his.

“定冠词the+形容词或分词”，表示某一类人动词用复数;若表示某一类东西时，动词用单数。The old are taken good care of there.

The beautiful gives pleasure to all.