can 和 could

聽講 could 和 can 意思一樣 , 但在文法上could比較有禮貌

係比較婉轉

但 could 係 can 既過去式
咁如果我想在現在式用 "可以" 黎問問題 , 又想有禮貌 (應該係比較婉轉)

咁可不可以用 could , 不用 can

可以
can的過去式She could play the violin when she was five. 她五歲時便能拉小提琴了。(用於假設語氣, 表示與事實相反的設想)能, 可以I wish I could go to France. 但願我能去法國。I would go if I could. 能去我就去。(表示可能性)可能That could be my train. 那可能是我要乘的火車。(用於婉轉語氣)能, 可以Could I smoke here? 我可以在這裡抽煙嗎?Couldn't you try it again? 你可否再試一下?

If you use 'could' for asking someone to do something, it is understood that it is in present tense although 'could' is the past tense form of 'can'.

其實我想講could冇話有冇禮貌
could就係can既過去式
你話用現在式用 "可以" 黎問問題,就要用can.
could同can冇話邊個有冇禮貌

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