原因狀語從句
連詞有：because as since now that等
(1) 區(qū)分because, as, since, for
① because表示人們不知道的直接的原因或理由，著重點在從句，其所引導(dǎo)的從句，為全句句意的中心所在。通常用于回答why引出的疑問句，語氣，除特別強調(diào)外，該從句一般位于主句后面，不能與so連用但是可以與so進行同義句轉(zhuǎn)換。
I didn't go aboard with her because I couldn't afford it.
我沒有和她一起出國是因為費用太高。
② as引導(dǎo)的原因狀語從句所傳遞的通常是已知信息，從句多位于主句之前，表示雙方那個已知的理由，如：
As I didn't know the way，I asked a policeman.
我不認(rèn)識路，因而問警察。
③ since引導(dǎo)的原因狀語從句多表示大家眾所周知的理由，如：
Since traveling by air is much faster, they decided to take a plane.
既然乘飛機旅行快得多，他們就決定坐飛機。
④ for表示的理由是附加的或推斷的，并非此原因，通常與主句用逗號隔開，不位于句首，如：
He must be not at home, for the telephone isn't answered.
用because, as, since, for 填空：
We'll have to go to bed early ___________ we'll start off early tomorrow.
___________ you know all about it, tell me please.
____________ all the seats were taken, I had to stand.
He must be at work, __________ the light in his office is still on.
Lily didn't go to school ___________ she was ill.
=_________________________________________________________.
(4) now that引導(dǎo)的原因狀語從句
Now that "因為;既然"，通?？梢院蛃ince換用。用來表示一種新的情況，再加以推論。如：
Now(that) you have passed your test, you can drive on your own.
你既已考試合格，就可以獨自開車了。
連詞有：because as since now that等
(1) 區(qū)分because, as, since, for
① because表示人們不知道的直接的原因或理由，著重點在從句，其所引導(dǎo)的從句，為全句句意的中心所在。通常用于回答why引出的疑問句，語氣，除特別強調(diào)外，該從句一般位于主句后面，不能與so連用但是可以與so進行同義句轉(zhuǎn)換。
I didn't go aboard with her because I couldn't afford it.
我沒有和她一起出國是因為費用太高。
② as引導(dǎo)的原因狀語從句所傳遞的通常是已知信息，從句多位于主句之前，表示雙方那個已知的理由，如：
As I didn't know the way，I asked a policeman.
我不認(rèn)識路，因而問警察。
③ since引導(dǎo)的原因狀語從句多表示大家眾所周知的理由，如：
Since traveling by air is much faster, they decided to take a plane.
既然乘飛機旅行快得多，他們就決定坐飛機。
④ for表示的理由是附加的或推斷的，并非此原因，通常與主句用逗號隔開，不位于句首，如：
He must be not at home, for the telephone isn't answered.
用because, as, since, for 填空：
We'll have to go to bed early ___________ we'll start off early tomorrow.
___________ you know all about it, tell me please.
____________ all the seats were taken, I had to stand.
He must be at work, __________ the light in his office is still on.
Lily didn't go to school ___________ she was ill.
=_________________________________________________________.
(4) now that引導(dǎo)的原因狀語從句
Now that "因為;既然"，通?？梢院蛃ince換用。用來表示一種新的情況，再加以推論。如：
Now(that) you have passed your test, you can drive on your own.
你既已考試合格，就可以獨自開車了。