狀語從句
　　狀語從句就是充當句子狀語的從句，它可分為時間、地點、方式、比較、原因、結果、目的、條件和讓步等從句。
　　1. 時間狀語從句
　　1)常用來引導時間狀語從句的連接詞有as, when, whenever, while, before, after, till, until, since, as soon as, hardly / scarcely … when, no sooner … than …等。如：
　　He made a mistake, but then he corrected the situation before it got worse.
　　Jack had scarcely / hardly seen me when he left the room.
　　2) 某些表示時間的副詞、名詞短語和介詞短語也可引導時間狀語從句。如directly, immediately, the instant, the moment, the minute, the day, the year, each / every time, next time, the first / second / last time, by the time等，如：
　　Directly I received your letter, I came back at once.
　　2. 地點狀語從句
　　地點狀語從句一般由where, wherever, everywhere和anywhere引導。如：
　　Wherever he went, he was warmly welcomed.
　　3. 原因狀語從句
　　原因狀語從句一般由because, as, since, now that, in that, seeing that, considering that, now that … but that, by reason that, for the reason that, on the ground that等引導。如：
　　As it is raining, let’s stay at home.
　　A gas differs from liquid in that it has no definite shape.
　　4. 結果狀語從句
　　結果狀語從句由so … that, such … that, so that, such that, so, that, to such a degree that, to such an extent that, with the result that等引導。
　　The shock was such that she was almost driven mad.
　　The temperature rose to such an extent that the firemen had to leave the house.
　　注：so和such位于句首時，主句需用倒裝語序。如：
　　So fierce was their dog that no one dared come near.
　　5. 目的狀語從句
　　目的狀語從句常由that, so that, in order that, lest, for fear that, in case等引導。從句謂語常由“can / could, may / might + 動詞原形”構成，有時也用“shall / should, will / would + 動詞原形”。如：
　　We left early so that we could catch the first train.
　　He ran away lest he (should) be caught.
　　6. 條件狀語從句
　　條件狀語從句由if, unless, only if(只要), if only(但愿), when(如果), suppose / supposing(假如), as / so long as(只要), given that(假設), provided / providing that(假如), granted / granting (that)(假定), on condition that(條件是……)等引導。如：
　　I’ll lend it to you as long as you handle it with care.
　　注：若主句為一般將來時，條件狀語從句中謂語需用一般現在時代替將來時。如：
　　If you are free tomorrow, I will go to see you.
　　但如果從句表示的是主語的意志、志愿或以you作主語表示請求時，則用will, would。如：I’d be very glad if you would come. 如果你肯來我會非常高興。
　　7. 讓步狀語從句
　　讓步狀語從句由as, though, although, even if / though, whatever, whoever, whichever, however, whether … or …, no matter + wh-詞, be, while, granted that, for all that等引導。如：
　　While / Although he has some shortcomings, he also has some good points.
　　Be it rain or shine, I must go.
　　注：as和though引導的讓步狀語從句通常用倒裝結構，as必須用倒裝結構，though可用也可不用倒裝。這種倒裝通常是把從句中的表語、狀語或謂語動詞放在句首。如：
　　Selfish as / though he is, he is not without merits. 盡管他自私，但不是沒有優點。
　　8. 方式狀語從句
　　方式狀語從句由as, as if / though, the way, how, as … as, not so / as … as, just as (… so)等引導。如：
　　It looks as if / as though it is going to rain.
　　Do it the way (that) you were told.