couldn't和can't的區(qū)別 兩者有何不同

couldn't和can't的區(qū)別：在請求語句里，couldn't比can't較委婉。在一般語句里，couldn't表過去時，can't表現(xiàn)在時。例句：I couldn't tell if he had been in a fight or had just fallen down.

couldn't和can't的區(qū)別

1、表示時間不同：couldn't代表的是過去的時間，表示以前某種情況不能發(fā)生或者某種行動無法完成。例如：“I couldn't finish my homework last night”。而can't則代表的是現(xiàn)在或者將來的時間。它指的是當(dāng)前或者未來某種事情是不可能發(fā)生的。例如：“I can't play basketball”。

2、語氣方面不同：在請求語句里，couldn't比can't較委婉。例如：“I couldn't disagree with you more”。

can't造句

1、You can't measure it.

2、You can't edit what you can't see.

3、I can't keep quiet.

4、I can't run faster.

5、We can't forgive his impoliteness.