和谐英语

您现在的位置是:首页 > 英语语法 > 语法教学

正文

动词原形还是非谓语动词

2016-06-05来源:和谐英语

请看下面的句子,空格处应填动词原形还是非谓语动词:

If they don’t understand it the first time, _________ over it again until they do.

A. going                   B. to go                    C. gone                    D. go

【分析】此题正确答案选D,其余几项均有可能被误选。空格前 if 引导的是一个条件状语从句,而在空格处无论是填A、B或C,它都是一个非谓语动词短语,而不是一个句子,这样一来,整个句子没有主句,从而导致结构不完整。若选D,则 go over it again until they do 则是一个句子(祈使句),在此用作主语。又如:

(1) If he likes to eat it, _________ him some more.

A. give                     B. giving                   C. given                    D. to give

(2) If anyone calls, _________ them I’m not at home.

A. tell                       B. telling                   C. told                      D. to tell

(3) When your mother comes back, _________ her to come to school at once.

A. ask                      B. asking                  C. asked                   D. to ask

(4) While the baby is sleeping, _________ your work as soon as possible.

A. finish                   B. finishing               C. finished                D. to finish

答案均选A,空格前分别为 if, when, while 引导的状语从句,空格处填动词原形,构成祈使句,用作句子主语。