什么是让步状语从句?请详细解释下!谢谢.

让步状语从句表示：虽然,尽管,即使等概念,由although（尽管）,though（尽管）,however（无论怎样）,whatever（无论什么）,whoever（无论谁）,whomever（无论谁）,whichever（无论哪个）,whenever（无论何时）,wherever（无论哪里）,whether（是否）,no matter (who,what,where,when,etc) （无论……）,even if（即使）,even though（即使）等词引导.
如：We won”t be discouraged even if(=even though) we fail ten times.我们就是失败十次也不泄气.
It was an exciting game,though / although no goals were scored.那是一场精彩的球赛,尽管一个球都没进.(though,although不能与 but连用)
Whether you believe it or not,it”s true.不管你信不信,这是真的.
However (=No matter how) expensive it may be,I”ll take it.无论它有多贵,我也要买下它.
Don”t let them in,whoever(=no matter who) they are.不管他们是谁,别让他们进来.
No matter what I say or how I say it,he always thinks I”m wrong.无论我说什么或怎么说,他总认为是我错.
特别提醒
1.no matter
what（who,which,when,etc.）与whatever（whoever,whichever,whenever,etc.）的区别：
当引导让步状语从句时,两者相同,可以互换,但当引导名词性从句（主语从句,宾语从句,表语从句和同谓语从句）时则只能用whatever（whoever,whichever,whenever,etc）.如上面最后两个例句可改为：
e．g． However pure the water looks,I do not want to drink it.
I want to marry the man I love,no matter who he may be.
下面句字不能用no matter结构:
Whoever comes back firs is supposed to win the prize.(主语从句)
I am ready to do whatever you want me to .（宾语从句）
2.as 引导让步状语从句的用法：
引导让步状语从句时,as意为“虽然,尽管”,通常从句要倒装,倒装的方法是将从句的表语或状语放在as之前,而用though引导让步状语从句时句字则不必倒装（口语中也可倒装）.
e.g.Heavily as it was raining outside,they started out very early.
Young as he is,he knows a lot=Though he is young 或Young though he is,he….
他虽然年轻,但懂得很多.(though 也有这种用法,可以替换as,但although没有这种用法)
though还可以用作副词,放在句末.如：
It was hard work;; I enjoyed it,though=It was hard work,but I enjoyed it.那工作很苦,但是我喜欢干.
3.用though/although,as 引导让步状语从句时,句中不能用but表示转折语气.
不能说：Though he looks weak,but he is healthy.
而要说：Though he looks weak,he is healthy.
或者说：He looks weak,but he is healthy.

就是加though,although(虽然)，表示让步

让步状语从句:
连接让步状语从句的连接词有：although, though, even if, even though, however, whatever, whenever, whoever, whichever.
1 Although (though) I gave him some advice, he didn’t take them.
2 John conti...