在請(qǐng)求語(yǔ)句里，couldn't比can't較委婉。在一般語(yǔ)句里，couldn't表過去時(shí)，can't表現(xiàn)在時(shí)。具體內(nèi)容跟小編一起來看看吧。

couldn't和can't有什么區(qū)別

1、表示時(shí)間不同：couldn't代表的是過去的時(shí)間，表示以前某種情況不能發(fā)生或者某種行動(dòng)無(wú)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(shí)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(yǔ)氣方面：在請(qǐng)求語(yǔ)句里，couldn't比can't較委婉。例如：“I couldn't disagree with you more”。

couldn't和can't的相關(guān)例句

can't例句：

1、I can't eat any more; I'm full up.

我不能再吃了，我已經(jīng)很飽了。

2、I don't want to leave, but I can't go on.

我不想離開，但我繼續(xù)不下去了。

3、I can't drink any more.

我不能再喝了。

4、Don't tell me you can't remember.

不要告訴我你記不起來了。

couldn't例句：

1、Jamie e-mailed me to say he couldn't come

杰米給我發(fā)了電子郵件，說他不能來了。

2、I couldn't imagine why he would want to be alone with me

我想象不出為什么他會(huì)想和我獨(dú)處。

3、They put a screen in front of me so I couldn't see what was going on.

他們?cè)谖颐媲柏Q了一面屏風(fēng)，所以我看不到發(fā)生了什么事情。

4、I couldn't get back to sleep.

我再也睡不著了。