You use hardly to modify a statement when you want to emphasize that it is only a small amount or detail which makes it true, and that therefore it is best to consider the opposite statement as being true.
scarcely , barely
I hardly know you.
我几乎不了解你。
I've hardly slept in three days.
我3天之中几乎没睡。
You use hardly in expressions such as hardly ever, hardly any, and hardly anyone to mean almost never, almost none, or almost no one.
We hardly ever eat fish.
我们几乎从不吃鱼。
Most of the others were so young they had hardly any experience.
其他人中的大部分都太年轻,几乎没任何经验。
You use hardly before a negative statement in order to emphasize that something is usually true or usually happens.
Hardly a day goes by without a visit from someone.
几乎没有哪一天没有来访者。
When you say you can hardly do something, you are emphasizing that it is very difficult for you to do it.
My garden was covered with so many butterflies that I could hardly see the flowers.
我的花园里到处都是蝴蝶,我几乎看不到花了。
You use hardly to mean 'not' when you want to suggest that you are expecting your listener or reader to agree with your comment.
We have not seen the letter, so we can hardly comment on it.
我们没见过那封信,所以很难对其加以评论。
You use hardly to mean 'no', especially when you want to express surprise or annoyance at a statement that you disagree with.
'They all thought you were marvelous!'—'Well, hardly.'
“他们都觉得你真是太棒了!” “喔,哪里哪里。”