原因狀語從句

　　I) because, since,和as引導(dǎo)的原因狀語從句

　　1. 其中because語氣最強，多表示所述理由是本句重點，強調(diào)別人未知的事實，故because引導(dǎo)的從句多放在句末，回答why的問句時，只能用because。

　　在語氣上since次之，as最弱。since和as表示的原因，多是已知的既成事實，原因以外的才是敘述的重點，因而兩者多用于句首。

　　As it is raining, lets stay indoors.

　　Since you have no license, you are not allowed to drive.

　　用強調(diào)句式強調(diào)原因狀語從句時，只能用because引導(dǎo)。

　　It was because he was careless that he failed.

　　在because引導(dǎo)的從句中，如果主句是否定句，而主句和后面的從句之間沒有逗號分開，這時not 修飾的是后面的整個從句。

　　The machine did not stop because the fuel was used up.

　　機器停了下來，并不是因為燃料用光了。

　　如果主句和從句間用逗號分開，意思就不同了。

　　I was not kind to him, because he was rude. 我對他不友好，因為他無禮。

　　II) for 和because 的區(qū)別

　　because 表示因果關(guān)系，語氣最強;而for引導(dǎo)的是并列句，它只是對前面分句進(jìn)行解釋， 說明推斷的理由，并且只能后置。

　　It must have rained last night, for the ground is wet this morning.

　　It is morning, for the birds are singing. 天亮了， 鳥兒在鳴叫。

　　結(jié)果狀語從句

　　so that, such that, so,等引導(dǎo)出結(jié)果狀語從句

　　注：I) 注意so和such后面跟的詞。其常見情況為：

　　so + adj. / adv.+ that; he is so clever that everyone likes him.

　　such a + adj. + n. + that + n. +that)

　　such + n. + that

　　若名詞前的修飾語為many, much, few, little則用so,不用such.

　　There is so much homework to do that I cant play computer games today.

　　There is such lot of homework to do that I cant play computer games today.

　　目的狀語從句

　　I) so that, in order that和in case, lest 等引導(dǎo)的目的狀語從句

　　so that , in order that 常與may, can, could, might等情態(tài)動詞連用

　　In order that he shouldnt wake up his wife, he came in quietly.

　　Ⅱ) in case, lest 引導(dǎo)的目的狀語從句多用虛擬語氣結(jié)構(gòu)：should + v. 原形，意為以防、以免。 例如：

　　He ran away lest he be caught.

　　I hid the book in case she should see it. 我把書藏起來，以防被她看到。

　　原因狀語從句

　　I) because, since,和as引導(dǎo)的原因狀語從句

　　1. 其中because語氣最強，多表示所述理由是本句重點，強調(diào)別人未知的事實，故because引導(dǎo)的從句多放在句末，回答why的問句時，只能用because。

　　在語氣上since次之，as最弱。since和as表示的原因，多是已知的既成事實，原因以外的才是敘述的重點，因而兩者多用于句首。

　　As it is raining, lets stay indoors.

　　Since you have no license, you are not allowed to drive.

　　用強調(diào)句式強調(diào)原因狀語從句時，只能用because引導(dǎo)。

　　It was because he was careless that he failed.

　　在because引導(dǎo)的從句中，如果主句是否定句，而主句和后面的從句之間沒有逗號分開，這時not 修飾的是后面的整個從句。

　　The machine did not stop because the fuel was used up.

　　機器停了下來，并不是因為燃料用光了。

　　如果主句和從句間用逗號分開，意思就不同了。

　　I was not kind to him, because he was rude. 我對他不友好，因為他無禮。

　　II) for 和because 的區(qū)別

　　because 表示因果關(guān)系，語氣最強;而for引導(dǎo)的是并列句，它只是對前面分句進(jìn)行解釋， 說明推斷的理由，并且只能后置。

　　It must have rained last night, for the ground is wet this morning.

　　It is morning, for the birds are singing. 天亮了， 鳥兒在鳴叫。

　　結(jié)果狀語從句

　　so that, such that, so,等引導(dǎo)出結(jié)果狀語從句

　　注：I) 注意so和such后面跟的詞。其常見情況為：

　　so + adj. / adv.+ that; he is so clever that everyone likes him.

　　such a + adj. + n. + that + n. +that)

　　such + n. + that

　　若名詞前的修飾語為many, much, few, little則用so,不用such.

　　There is so much homework to do that I cant play computer games today.

　　There is such lot of homework to do that I cant play computer games today.

　　目的狀語從句

　　I) so that, in order that和in case, lest 等引導(dǎo)的目的狀語從句

　　so that , in order that 常與may, can, could, might等情態(tài)動詞連用

　　In order that he shouldnt wake up his wife, he came in quietly.

　　Ⅱ) in case, lest 引導(dǎo)的目的狀語從句多用虛擬語氣結(jié)構(gòu)：should + v. 原形，意為以防、以免。 例如：

　　He ran away lest he be caught.

　　I hid the book in case she should see it. 我把書藏起來，以防被她看到。