could
/kʊd/modal verb
1- past of
CAN1 .CAN1 的过去式。
1.1
- used to indicate possibility可能：
they could be right
他们可能是对的
I would go if I could afford it.
如果负担得起我会去的。
1.2
- used in making polite requests（用于礼貌的请求）可以; 能够：
could I use the phone?
我可以用这个电话吗？
1.3
- used in making suggestions（用于提建议）可以 ：
you could always ring him up.
你可以随时给他打电话。
1.4
- used to indicate annoyance because of something that has not been done（对未做的事情表示恼怒）本可以; 本来应该：
they could have told me!
他们本该告诉我的！
1.5
- used to indicate a strong inclination to do something（表示做某事的强烈愿望）想要：
he irritates me so much that I could scream.
他让我如此恼怒, 以至于我都想尖叫了。