知識點總結
是用來說明引起主句這個結果的原因的從句，在初中階段引導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，因為我生病了。
2. Since everybody is h ere, 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.
原因狀語從句應注 意的問題
1、because , since , as , for,辨析
1）because語勢，用來說明人所不知的原因，回答why提出的問題。當原因是顯而易見的或已為人們所知，就用as或 since。
I did n't go, because I was afraid.
Since /As the weather is so bad, we have to delay our journey.
2）由because引導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引導的從句在主句前，for引導的從句在主句后。例： As the weather is cold, I stay at home.（同義句） I stay at home, for the weather is cold.
2、because習慣上不與so連用
漢語習慣上說"因為…所以…"，但英語習慣上卻不能將 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 h ome. 因為下雨，所以我們呆在家里。
3、because 從句與 because of短語的轉換
Because引導的原因狀語從句有時可與because of 短語轉換，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 th ere. 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 fou nd it increasin gly difficult to read, ____ hi s eyesight was beginning to fail.
A. and B. for C. but D. or
解析： "his eyesight was beginning to fail"是"he found it increasingly difficult to read"的原因， 因此本題應選用可以表示原因的連詞for引導原因狀語從句。
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引導的原因狀語從句有時可與because of 短語轉換，because of后跟的是短 語 ，because后跟的是句子。
典型例題：He didn't go to work the heav y 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
是用來說明引起主句這個結果的原因的從句，在初中階段引導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，因為我生病了。
2. Since everybody is h ere, 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.
原因狀語從句應注 意的問題
1、because , since , as , for,辨析
1）because語勢，用來說明人所不知的原因，回答why提出的問題。當原因是顯而易見的或已為人們所知，就用as或 since。
I did n't go, because I was afraid.
Since /As the weather is so bad, we have to delay our journey.
2）由because引導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引導的從句在主句前，for引導的從句在主句后。例： As the weather is cold, I stay at home.（同義句） I stay at home, for the weather is cold.
2、because習慣上不與so連用
漢語習慣上說"因為…所以…"，但英語習慣上卻不能將 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 h ome. 因為下雨，所以我們呆在家里。
3、because 從句與 because of短語的轉換
Because引導的原因狀語從句有時可與because of 短語轉換，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 th ere. 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 fou nd it increasin gly difficult to read, ____ hi s eyesight was beginning to fail.
A. and B. for C. but D. or
解析： "his eyesight was beginning to fail"是"he found it increasingly difficult to read"的原因， 因此本題應選用可以表示原因的連詞for引導原因狀語從句。
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引導的原因狀語從句有時可與because of 短語轉換，because of后跟的是短 語 ，because后跟的是句子。
典型例題：He didn't go to work the heav y 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