could
第三人称
can
过去式
could
过去完成时
could
1
可以, 能
used as the past tense of ‘can’
- When I was younger, I could run faster.
当我年轻时，我能跑得更快。
- Yesterday, I could see the stars clearly in the night sky.
昨天，我可以清晰地看到夜空中的星星。
- Before the accident, he could lift heavy weights easily.
在事故之前，他可以轻松举起重物。
- When I was a child, I could climb trees without any fear.
当我还是个孩子的时候，我可以毫无恐惧地爬树。
- He could solve complex math problems effortlessly in his youth.
他年轻时能毫不费力地解决复杂的数学问题。
2
你可以, 你能
used to ask if one can do something
及物动词
- Could you please pass me the salt?
你能把盐递给我吗？
- Could you help me with my homework?
你能帮我做作业吗？
- Could I borrow your pen for a moment?
可以借你的笔用一下吗？
- Could you tell me how to get to the nearest post office?
你能告诉我怎么去最近的邮局吗？
- Could you open the window?
你能打开窗户吗？
3
可能, 可以
used to show the possibility of something happening or being the case
4
可以, 能
used to present an offer or recommendation