请看下面一道考题：
______, he talks a lot about his favorite singers after class.
A. A quiet student as he may be B. Quiet student as he may be
C. Be a quiet student as he may D. Quiet as he may be a student
这道题很有一定难度。具体说来，它主要涉及两个考点：一是让步状语从句倒装后的词序问题。让步状语从句之所以要采用倒装结构，主要是为了强调位于句首的名词、形容词、副词、动词等，其词序形式为：被强调的成分 as / though 主语 动词。二是在倒装的让步状语从句中，位于句首的单数可数名词是否带冠词的问题。按照英语习惯，英语中的单数可数名词在泛指时，一般要有不定冠词的修饰，但是位于倒装让步状语从句句首的单数可数名词是个例外，即使泛指其前也不加不定冠词。由此可知，上面这道考题的答案应为B。
为了帮助同学们全面掌握让步状语从句的倒装用法，本文将这类语法现象归纳为以下五种句型：
一、名词 as / though 主语 动词
King as he was, he was unhappy. 他虽是国王，但他并不幸福。
Child as he is, he knows to help other. 他虽是个孩子，但却知道帮助别人。
Teacher though he is, he can't know everything. 他虽然是老师，但也不可能什么都懂。
【说明】其中的动词通常为连系动词，也就是说位于句首的名词是其后连系动词的表语。另外，要特别注意位于句首的名词前习惯上不用冠词，即使其前有形容词修饰也不用冠词。比较：
Boy as [though] he is, he likes to play with girls.=Though [Although] he is a boy, he likes to play with girls.他虽是男孩，却喜欢与女孩子玩。
Strong man as [though] he is, General Botha has been severely put to the test during the past few weeks.= Though [Although] he is a strong man, General Botha has been severely put to the test during the past few weeks.
波赛将军虽然坚强，但在过去的数周里也受到了严峻的考验。
二、形容词 as / though 主语 动词
Successful as he is, he is not proud.
他虽然成功，但不骄傲。
Improbable as it seems, it's true.
虽然看起来不太可能，但却是真的。
Stupid as it sounds, I was so in love with her that I believed her.
尽管听起来很愚蠢，我是如此爱她竟然相信了她的话。
Patient as he was, he didn't like waiting that long.
他虽说有耐心，也不愿等这么长。
Beautiful though the necklace was, we thought it was over-priced.
那条项链虽然很漂亮，我们认为价钱太高。
【说明】其中的动词也通常为连系动词，也就是说位于句首的形容词是其后连系动词的表语。
三、副词 as / though 主语 动词
Much as I like Paris, I couldn't live there. 尽管我喜欢巴黎，但我不能住在那里。
Hard though they tried, they couldn't make her change her mind.
尽管他们做了很大努力，却没法让她改变主意。
Fast as you read, you can't finish the book in two days.
尽管你读得很快，你总不能在两天之内就读完这本书。
He was unable to make much progress, hard as he tried.
尽管他做了努力，却未能取得很大进步。
【说明】有的词典将much as 作为习语看待，认为它是一个用以引导让步状语从句的复合连词。再如：
Much as I admire him as a writer, I do not like him as a man.
他作为一名作家我很佩服他，但我却不喜欢他这个人。
Much as I like you, I couldn't live with you.
我尽管很喜欢你, 却不能和你在一起生活。
四、动词原形 as / though 主语 动词
Object as you may, I'll go.
纵使你反对，我也要去。
Try as he might, he couldn't solve the problem.
尽管他想方设法，却未解决这个问题。
Search as they would, they would find nobody in the house.
无论怎样搜查，他们在房子里仍然没有找到一个人。
Dislike him as we may, we must acknowledge his greatness.
尽管我们不喜欢他，但必须承认他的伟大。
Lose money as I did, we got a lot of experience.
钱虽然丢了，我们却得到了许多经验。
Fail in the election as he did, he became famous for his fiery speech against slavery. 尽管落选了，但他却以其反对奴隶制的激烈演说而出了名。
【说明】主语后的动词通常为may, might, would, did 等情态动词或助动词(若表示情态意义，则选用情态动词；若陈述事实，则用did, do 等助动词)。
五、分词 as / though 主语 动词
Raining hard as it is, I'm going out for a walk. 虽然正在下着大雨，我还是要出去散步。
Surrounded as we were by the enemy, we managed to march forward.
虽然我们被敌人包围着，但我们还是设法前进了。
Munching the apple as he was, he had got an eye for all John's movements.
他尽管在一个劲地嚼着苹果，但仍警惕着约翰的一举一动。
【三条补充说明】
1. 这类倒装的让步状语从句可用as, though 来引导，但不能用although来引导；但是，未倒装的让步状语从句则可用though, although来引导，而不能用as来引导。也就是说，although引导让步状语从句时不能倒装，as引导让步状语从句时必须倒装，而though引导让步状语从句时可以倒装也可以不倒装。如：
虽然很晚了，但我们还是继续工作。
正：Late as [though] it was, we still went on working.
正：Though [Although] it was late, we still went on working.
误：Late although it was, we still went on working.
误：As it was late, we still went on working.
2. 上面提到的倒装结构有时也可用来表示原因，区别的办法主要看句子的内容：让步从句的内容大多数与主句在意义上相反，而原因从句则与主句之间有因果关系。比较：
Tired as he was, he sat up late studying at night.
昨晚他虽然很疲倦了，但还是学习到很晚才睡。(表让步)
Tired as he was, he went to bed early.
因为很累，所以他睡得很早。(表原因)
Young as he was, he was equal to the task.
他虽年轻，却能胜任这项工作。(表让步)
Young as he was, he was not equal to the task.
他因为年轻，所以不能胜任这项工作。(表原因)
3. 在美国英语中，人们通常用as…as引导让步状语从句。如：
Cold as it was, we went out.=As cold as it was, we went out.
尽管天气冷，我们还是出去了。
Successful as he is, he is not proud.=As successful as he is, he is not proud.
他虽成功了，但不骄傲。
