情态动词考题的两个侧重点
一般情态动词考题的考查主要涉及两个方面，一是对情态动词所用句型的考查，二是对情态动词在一定的语境中的意义的考查。如：
1. “Is John coming by train?” “He should, but he ________ not. He likes driving his car.”
A. must B. can C. need D. may
最佳答案为D。may 表推测，may not 意为“可能不(会坐火车来)”。句中的 He should 为 He should come by train 之省略，由于其后出现转折连词 but，说明语意有变化，再结合下文的 He likes driving his car，便可决定此题选D。注意，不能选B，因为can表示推测时通常不用肯定陈述句。
2. “I heard they went skiing in the mountains last winter.” “It ____ true because there was little snow there.”
A. may not be B. won’t be C. couldn’t be D. mustn’t be
此题最佳答案为C，主要由下文的 because there was little snow there 这一语境所决定，既然“没下什么雪”，那么“滑雪”就应是“不可能”，所以选 couldn’t be，即选C。
3. “Do you think he is lazy?” “I ________ so once, but I don’t now.”
A. may have thought B. can have thought
C. may think D. might think
答案选A。从答话人的语境可知，空格处的意思“曾经这样想过”，即对过去情况作推测，故应用“情态动词+动词完成式”；又因为 can 表推测不用于肯定句，故选A。