一、狀語從句可以分為很多種類別，其中，表示原因的從句叫做原因狀語從句，引導(dǎo)原因狀語從句的從屬連詞主要有because, as, since,seeing (that), now (that), considering (that)，in that等：例如：
1. The woolly shrank because it was washed badly.
毛衣因洗的方法不好而縮水。
2.I can’t get to sleep because of the noise outside.
由于外面聲音嘈雜我睡不著。
3.Since we’ve no money, we can’t buy it.
由于我們沒錢，我們無法購(gòu)買它。
4.Seeing that it’s raining, we’d better stay indoors.
既然外邊在下雨，我們最好待在室內(nèi)。
5.Now that you are here, you’d better stay.
你既然來了，最好還是留下吧(既來之，則安之)。
需要注意的是：除以上提到的大家比較熟悉的引導(dǎo)原因狀語從句的從屬連詞外，when有時(shí)也可引導(dǎo)原因狀語從句(when表示“既然”)，例如：
I won’t tell you when you won’t listen. 既然你不想聽，我就不告訴你了。

二、在引導(dǎo)原因狀語從句時(shí)，not…because結(jié)構(gòu)中的否定詞有時(shí)否定主句，有時(shí)否定從句，一般要根據(jù)句子的意思作出正確或合乎邏輯的理解。若not否定主句，最好在because之前用逗號(hào)，否則會(huì)引起歧義，例如：
I didn’t go, because I was afraid.
我沒有去是因?yàn)榕隆?br> 不過若because之前有just修飾，一般認(rèn)為not 是否定從句的：
You shouldn’t get angry just because some people speak ill of you.
你不要因?yàn)橛腥苏f你壞話而生氣。

三、1、在表達(dá)原因狀語從句中，because習(xí)慣上不與so連用，例如：
因?yàn)橄掠?，所以我們呆在家里?br> 正：Because it was raining, we stayed at home. / It was raining, so we stayed at home.
誤：Because it was raining, so we stayed at home.
2、because從句與 because of短語的轉(zhuǎn)換
Because引導(dǎo)的原因狀語從句有時(shí)可與because of 短語轉(zhuǎn)換，because of后可以加好的原因，也可以加壞的原因，例如：
He can’t come because he is ill. / He can’t come because of his illness.
他因病不能來。
I said nothing about it because his wife was there. / I said nothing about it because of his wife’s being there.
因?yàn)樗拮釉谀莾海覍?duì)此事只字未提。
?