11. 情态动词后何时接一般式, 何时接完成式

The plant is dead. I ______ it more water.

A. should give           B. should have given  C. must give              D. must have given

此题应选 B。从句意上看, 植物既然已死了, 那么后句的意思应该是：本来应该多浇水, 但却没有多浇水(这是一种遗憾), 所以只能选B。

谈论现在的情况, 情态动词后接动词原形：谈论已经发生的情况或本来应该发生但却没有发生的情况等, 情态动词后要接动词的完成式。请做以下各题：

1. Jenny ____ have kept her word, I wonder why she

changed her mind.

A. must                    B. should                  C. need                     D. would

2. We ____ last night, but we went to the concert

instead.

A. must have studied                                  B. might study

C. should have studied                               D. would study

3. He should not ____ me your secret, but he meantno harm.

A. have told                                               B. tell

C. be telling                                               D. having told

4. I told Sally how to get here, but perhaps I____ it out for her.

A. had to write                                          B. must have written

C. should have written                               D. ought to write

答案：1. B 2. C 3. A 4. C