2013年职称英语考试语法指导:情态动词6" F+ U' {$ M- h8 ]* H. |4 c
(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: ' i/ ^- \7 D( g7 i( Q5 F2 Z
1)According to the weather forecast, it may rain tomorrow. * f+ x3 }' B' R# |9 Z9 ? 2) Any man with a little sense can see that he is wrong. 外语学习网 ' Q( a6 ]/ ~( ?( }* y" ]. |5 h% C; | (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: 3 o [4 k3 a! s8 w% k. ~9 h “May we leave now?” “No, you mustn't. You haven't finished your home work yet.” * k7 y1 L9 i# w) o
4. can 和 be able to : s1 I' ]1 w+ s% _ 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: 5 @/ c) }+ V, u" ` 1)My grandma is over seventy, but she can still read without glasses. - e0 c* |, O. B- o k' L P3 m
2)He is able to give up his bad habits.