助动词 “could”
could, negative couldn't
- 可能
If we hurry, we could catch the last train home.
- 可以(用于礼貌地请求许可)
Could I use your phone to make a quick call?
- 可以(用于礼貌地请求他人采取行动)
Could you please pass the salt?
- 可以(用于提供建议或建议)
For your headache, you could take a pain reliever.