按語法功能劃分啊.
用在主句中動詞后起賓語作用的就是賓語從句,如 I know he is a student 中的 he is a student .
用在主句中 be 動詞后起表語作用的就是表語從句,如 The new was that we had succeeded 中的 that we had succeeded .
出現(xiàn)在主句中主語位置,因而起主語作用的,就是主語從句,如 Whether he is a student is not known yet 中的Whether he is a student .
用在某名詞后做那個名詞的同位語的就是同位語從句,如 The news that we had succeeded was exciting 中的 that we had succeeded .
修飾主語句中某動詞 （主要是謂語動詞）起狀語作用的就是狀語從句,如 We left him alone because we saw use persuading him 中的 because we saw use persuading him .
修飾主句中某名詞起定語作用的就是定語從句,如 The book that I bought yesterday is interesting 中的 that I bought yesterday .
就說這么些吧,希望對你有用.