区别：
1、在动词不定式之前只能用whether。
I can’t decide whether to stay. 我不能决定是否留下。
2、在whether …… or not 的固定搭配中。
I want to know whether it’s good news or not . 我想知道是否是好消息。
3、在介词后,只能用whether。
His father is worried about whether he lose his work . 他的父亲担心是否会失去工作。
4、宾语从句放在句首表示强调时，只能用whether。
Whether they can finish the work on time is still a problem . 他们是否能准时完成这项工作还是个问题。
妆罢低声问夫婿as或though引导的倒装句
一、名词+as / though+主语+动词
杜德智
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 Bot
ha 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。
东临碣石以观沧海全诗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。
whether是什么意思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，alt
hough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：
在街角的咖啡店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。
why 可以表示原因或理由，how 只能表示方式、程度、范围，但不能表示原因。
如果用 why 引导宾语从句，从句表示的是 “为什么是这种情况” ，即 “…的原因”。如：
I know why you left. 我知道你离开的原因
He wondered why you disliked him so much.他想知道你那么讨厌他的原因。
如果用 how 引导宾语从句，从句表示的是“如何/怎么样产生这种情况”，即即“…的方式/办法/措施”、“…的程度或范围”。如：
I know how you left. 我知道你是以什么方式离开的
万佛堂
He wondered how you disliked him. 他想知道你讨厌他的程度。
  就你提到的例子而言，从语法角度来说，用 why 和 how  引导都没有错误，它们的意思分别如下：
Last week a reporter from a magazine interviewed her and asked (why) she kept so young and beautiful. 上周一家杂志社的记者采访了她，问她为什么保持如此年轻和漂亮状态。
Last week a reporter from a magazine interviewed her and asked (how) she kept so young and beautiful. 上周一家杂志社的记者采访了她，问她怎么样就保持了如此年轻和漂亮的状态