I could not sew. 我怎么也不会做针线活(可补上「即使我试着去做」)
Could you come and see me tomorrow? 明天来好吗?(比will you...?would you...? 更有礼貌)
I could laugh [could have danced] for joy. 我喜欢得想笑起来[跳起舞]
You could at least have called me up, couldn't you? 你本来至少可以给我打电话,不是吗?