对现在事件的否定推断,可以用can't或couldn't加上动词be的现在式或者可以用can't/couldn't加上动词的进行式表示:
Child:Can I have some sweets?I'm hungry.
孩子:我可以吃些糖果吗?我饿了。
Mother:You can't/couldn't be hungry. You've just had dinner.
母亲:你不会饿的。你刚吃过饭。
1、I can't eat any more; I'm full up.
我不能再吃了,我已经很饱了。
2、I don't want to leave, but I can't go on.
我不想离开,但我继续不下去了。
3、I can't drink any more.
我不能再喝了。
1、Jamie e-mailed me to say he couldn't come
杰米给我发了电子邮件,说他不能来了。
2、I couldn't imagine why he would want to be alone with me
我想象不出为什么他会想和我独处。
3、They put a screen in front of me so I couldn't see what was going on.
他们在我面前竖了一面屏风,所以我看不到发生了什么事情。