新东方考研语法讲堂160

考研网

2.如果主语是一个抽象概念(如不定式、动名词、主语从句等)谓语动词用单数形式。如果主语是用and连接的两个或多个抽象概念，谓语动词用复数形式。
    如：Swimming jogging and cycling are all goad farms of sports exercises.游泳、慢跑和骑自行车都是很好的运动形式。
    To live to eat is not a very goad attitude toward life. 活着就是为了吃不是好的生活态度。
    To live to eat and to eat to live are very different attitudes toward life.
    以what，who，why，haw, whether等wh一词引起的从句做主语时，谓语动词通常用单数;由and连接的两个主句如果指两件事，动词用复数。
    例如:What he is doing is not clear yet他在干什么还不清楚
    What he is doing and whether I know him are two different things.他在干什么和我是否认识他是两件不同的事。
    What she told me is none of your business. 她和我说的什么用不着你管。
    What she told me and what she told you are totally different things.
    以what从句为主语的“主一系一表SVC"句型中，如果主句的表语是复数，主句谓语动词用复数形式;what从句本身是复数意义，主句谓语动词也可用复数。
    如：What I need buy now are four tea cups and a pair of sports shoes.
    我需要买的是四只茶杯和一双运动鞋。
    What were thought to be five dogs were actually five sheep.
    被认为是五条狗的东西实际上是五只羊。