好多人都会被情态动词搞混，can和Could，may和might，should和must，什么时候用哪个，我们今天来捋一捋。
我们用might表示可能会发生的事。比如说：
Where are you going for your holidays?
--I'm not sure. I might go to New York.
我可能会去纽约。
It might rain.
可能会下雨。
may和might有什么区别呢？其实两者都可以同样使用，表示不确定，可能会发生的事。比如：
I might go to the cinema this evening.
=I may go to the cinema this evening.
我可能今晚会去电影院。
Sue might not come to the party tonight.
=Sue may not come to the party tonight.
Sue今晚可能不会来参加派对了。
我们用can来表示“知道怎么做...”或者“对某人来说，...是可操作的”。
I can play guitar, but I can't play piano.
我会弹吉它，但是我不会弹钢琴。
Can you swim?
--Yes, but I'm not a very good swimmer.
如果是在过去时态里，我们就用could/ couldn't。
When I was young, I could run very fast.
当我年轻的时候，我可以跑得很快。
Before Anna came to England, she couldn't understand much English, but she can understand everything now.
Anna去英国前不懂太多英语，但是现在她能懂所有事。
