Hard as/though I tried to explain，he still didn't understand.

尽管我尽力向他解释，他仍然不懂。

Try as he might，he couldn't solve the problem.

尽管他很努力，但还是无法解决这个问题。

(3)though可以当副词用，但although不可当副词用。

I do have a problem though.

不过，我的确有一个问题。

(4)while引导让步状语从句时，一般位于主句之前。

2.even if，even though引导的让步状语从句

even if，even though引导让步状语从句时，意为"即使"。

Even if/though you fail，you will gain experience.

即使你失败了，你也会得到一些经验的。

3."特殊疑问词＋－ever"和"no matter＋特殊疑问词"引导的让步状语从句

"no matter＋疑问词"或"疑问词－ever"所引导的让步状语从句均表示"无论；不管"，可以互换。

No matter what/Whatever happened，he would not mind.

无论发生什么，他都不会介意的。

Your mother will wait for you however/no matter how late it is.

不管多晚你妈妈都会等着你。

[温馨提示] "no matter＋疑问词"结构只能引导让步状语从句，而"whatever，whichever，whoever，whomever"还可以引导名词性从句。

Whatever (＝No matter what) you say，I won't believe you.(whatever 引导让步状语从句)

I'll eat whatever(≠no matter what) you give me.(whatever引导宾语从句)

4.whether...or...引导的让步状语从句

whether...or...引导让步状语从句时，表示"不论是否；不管是......还是......"之意。