知識點總結(jié)

是用來說明引起主句這個結(jié)果的原因的從句，在初中階段引導(dǎo)原因狀語從句的從屬連詞主要的有because, as, since,for等。例如：

1.I didn’t go to school yesterday because I was ill. 我昨天沒去上學(xué)，因為我生病了。

2. Since everybody is here, let’s begin our meeting. 既然大家都來了, 讓我們開始開會吧.

3. As you are in poor health, you should not stay up late. 既然你身體不好, 你就不該熬夜.

4.I asked her to stay to tea, for I had something to tell her. 我請她留下來喝茶,因為我有事要告訴她.

原因狀語從句應(yīng)注意的問題

1、because , since , as , for,辨析

1）because語勢最強(qiáng)，用來說明人所不知的原因，回答why提出的問題。當(dāng)原因是顯而易見的或已為人們所知，就用as或 since。

I didn’t go, because I was afraid.

Since /As the weather is so bad, we have to delay our journey.

2）由because引導(dǎo)的從句如果放在句末，且前面有逗 號，則可以用for來代替。但如果不是說明直接原因，而是多種情況加以推斷，就只能用for。例：

He is absent today, becaus e / for he is ill. He must be ill, for he is absent today.

3） as和for的區(qū)別：通常情況下，as引導(dǎo)的從句在主句前，for引導(dǎo)的從句在主句后。例： As the weather is cold, I stay at home.（同義句） I stay at home, for the weather is cold.

2、because習(xí)慣上不與so連用

漢語習(xí)慣上說“因為…所以…”，但英語習(xí)慣上卻不能將 so與because 連用：

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. 因為下雨，所以我們呆在家里。

3、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可與because of 短語轉(zhuǎn)換，because of后加的原因可以為好或壞 ，但最正規(guī)的還是because。

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. 因為他妻子在那兒，我對此事只字未提。

常見考法

對于原因狀語從句的考查，多以單選和完形填空的形式，從連詞的意義角度讓大家選擇連詞。

典型例題：He found it increasingly difficult to read, ____ his eyesight was beginning to fail.

A. andB. for  C. but  D. or

解析： “his eyesight was beginning to fail”是“he found it increasingly difficult to read”的原因， 因此本題應(yīng)選用可以表示原因的連詞for引導(dǎo)原因狀語從句。

答案： B

誤區(qū)提醒

除了because , since , as , for這四個詞的辨析外，對于because 從句與 because of短語的區(qū)分也是難點之一。Because引導(dǎo)的原因狀語從句有時可與because of 短語轉(zhuǎn)換，because of后跟的是短語 ，because后跟的是句子。

典型例題：He didn't go to workthe heavy rain.

A .because  B.because of  C.so  D.since

解析：題干的意思是“ 由于那場大雨，他沒有去上班”，the heavy rain.表示原因，排除C； since和because 表示原因，后面跟的是從句，也就是說必須是一個完整的句子，本題中the heavy rain沒有主語和謂語，.只是一個短語，所以排除A和C；because of表示“由于···”，后跟名詞、代詞或短語。

答案：B