Question

at all放在句中是什么意思

我知道放在句末是加强否定，那句中呢？

Answer 1

同样也是加强否定

He is not at all alive to the danger he is in.
他完全没有意识到他处境的危险。

I'm not at all sure, actually.
实际上我根本不能肯定。

Answer 2

at all

完全,根本

查询剑桥辞典
例句与用法:
It's not at all that bad.
这根本没有那么坏。
Whatever is worth doing at all is worth doing well.
任何值得做的事就值得做好。
I'm not at all sure, actually.
实际上我根本不能肯定。
You might as well not know a thing at all as know it only a little.
只知道一点点，不如完全不晓得。
As a matter of fact, I didn't know him at all.
事实上，我根本不认识他。
He is not at all alive to the danger he is in.
他完全没有意识到他处境的危险。
It doesn't matter at all.
这根本没什么关系。
I don't think that's a bad idea at all.
我看这完全不是个坏主意。