（1）although與though可以引導讓步狀語從句,不能與but連用,但可以與yet連用。

Although they are poor,（yet）they are warm-hearted.

（2）even if或even though引導讓步狀語從句,表示“即使”,“縱然”,用來使人注意下文所強調內容的性質。

I'll get there even if（though）I have to sell my house to get enough money to go by air.

（3）no matter后接上who、what、where、how等疑問詞,也可以在這類疑問詞后面加上ever構成whoever、whatever、wherever、however等。

Don't trust him, no matter what/whatever he says.

Whoever breaks the law will be published.

No matter how hard the work is, you'd better try to do it well.

（4）as也可以引導讓步狀語從句。要用倒裝。

Child as（though）he is, he knows a lot.

Much as I like it, I won't buy.

Try as he would, he couldn't lift the heavy box.