2020专四词汇语法考点练习题：情态动词
专四词汇语法题即专四语言知识题，题型为选择题供20题，考察考生词汇、语法、句法、短语，新东方在线英语专四频道整理了九类专四词汇语法考点练习题附答案解析供考生们练习。
1. You ______ Jim anything about it. It was none of his business. (2004)
A. needn’t have told B. needn’t tell C. mustn’t have told D. mustn’t tell
A，needn’t have done表示本不必做而做了。没有mustn’t have done的形式，但可以说can’t have done，表示不大可能。
2. He ______ the 8:20 bus because he didn’t leave home till 8:25. (1994)
A. couldn’t have caught B. ought to have caught
C. shouldn’t have caught D. must not have caught
A，couldn’t have done表示不可能做了某事。
3. He _____ unwisely, but he was at least trying to do something helpful. (1999)
A. may have acted B. must have acted C. should act D. would act
A，may have done表示过去可能做过某事，B表示一定做过，推测的可能性很大。