Frelyx: 【学习笔记】EGU

could的用法

could is the past of can
use could with "see/hear/smell/taste/feel/remember/understand"
use colud to say sb had the general ability or permission to do something
use be able to do if we are talking about what happened in a particular situation.
couldn't is possible in all situations.
use could to talk about possible actions now or in the future.(especially to make suggestion)
could is "sure" than can if we using them to talk about possible.
could have means you don't really mean what you say.
I'm so angry with him, I could kill him.
use could have for things which were possible but did not happen.
could also means "would be able to"
could have done = would have been able to (do)

例句：

Perter is a keen musician, he plays the flute and he can also play the piano.
The weather is nice now but it could change later.
Ken could have played tennis on Monday afternoon.

Frelyx