2013年职称英语考试语法指导:情态动词6 Q% j4 \2 \% q1 v" P' U( p (1)can, could, may, might都可以表示可能性。can, could表示潜在的可能性或理论上或逻辑判断上存在的可能性;而may, might则表示事实上的可能性。此外,can还具有“有能力”的意思,而may与might则不具此意。例如: , G* Y/ N# ?* h# Z+ m! T 1)According to the weather forecast, it may rain tomorrow. 9 K6 \2 f/ I' q; F3 Y 2) Any man with a little sense can see that he is wrong. 外语学习网; r0 L* S; w! s; P0 A
(2)May I / we …?这一类疑问句的肯定回答为Yes, please.或Certainly;否定回答为Please don't.或No, you mustn't. 例如: . l. ~2 d+ P/ u. [ “May we leave now?” “No, you mustn't. You haven't finished your home work yet.” ! m( f# C7 G- h% N
4. can 和 be able to - S0 C& y7 i3 @$ F! r* r& Y1 d' P
can 与 be able to 都可以表示能力,但两者在用法上有点差异:can (could)表示主观能力,不表示意愿,它的将来时用will be able to; be able to表示主观意愿,强调要克服困难去做某事。例如: . P' g9 x: m! A: w) M& Q 1)My grandma is over seventy, but she can still read without glasses. , j& Y4 P" r2 d8 o8 K
2)He is able to give up his bad habits.