用at all去强调可达到四两拨千斤之效果

用于否定句，意为：根本不、一点也不。如：

It wasn’t difficult at all. 这一点也不难。

There was nothing to eat at all. 根本没什么可吃的。

To try and fail is better than not to try at all. 尝试而失败也比不尝试好。

He speaks an English that I can barely understand at all. 他说的英语，我简直听不懂。

It’s quite extraordinary; I can’t understand it at all. 这件事太不寻常了，我根本没法理解。

He made out that he was a student looking for a job. We later learnt that this wasn’t true at all. 他说他是个在找工作的大学生。后来我们获悉这根本不是事实。

注：在否定句中，at all 可位于句末，也可跟在否定词后。如：

He isn’t tired at all. / He’s not at all tired. 他一点也不累。

另外，在口语中单独说 not at all, 可用来回答感谢或道歉。如：

A：Thank you very much. 多谢你了。

B：Not at all. 不客气。

A：I’m sorry to keep you waiting. 对不起，让你久等了。

B：Oh, not at all. 噢，没关系。

用于疑问句，意为：到底、究竟、难道不。如：

Are you at all worried about it? 你难道对此不担心吗?

Do you play poker at all? 你会打扑克吗?

Have you read any of the report at all? 那份报告你到底有没有读一点?

用于条件句，意为：假若、既然、即使、反正。如：

If you do it at all, do it well. 既然要做，就把它做好。

He’ll come before supper if he comes at all. 他要是来，准在晚饭以前。

用于肯定句， 意为：不管怎样，竟然，很（都是加强语气，强调之意）。如：

I was surprised at his coming at all. 我很奇怪， 他竟然来了。

You can come whenever you like---any time at all. 你什么时候想来就来——无论什么时候都行。