有三大類
1.名詞性從句 2.定語從句 3.狀語從句
名詞性從句中分：
1.主語從句：例,it is important to read book.(形主it作主語,真正的主語是to read book)
that air has pressure was known long ago.(關(guān)聯(lián)詞that引導(dǎo)的句子that air has pressure作主語從句)
2.賓語從句：I think it necessary that he should do his homework.(形式賓語it引導(dǎo)的)
I'm sure that my test will succeed.(sure后用that引導(dǎo)的賓從)
3.表語從句：系動(dòng)詞后的從句
it may be as you say(be是系動(dòng)詞,后面用as引導(dǎo)的)
this is that he is too young to go to school.(有系動(dòng)詞is,后面由that引導(dǎo)的表語從句)
4.同位語從句：同位語從句是對前面名詞的解釋說明,如：
The facts that he had done his homework.(事實(shí)就是he had done his homework,是對前面the facts的解釋,是什么事實(shí))
定語從句：在句子中起定語作用,修飾劇中的名詞或代詞的從句叫定從
例：the man (who is shaking hands with my father) is my teacher.(括號(hào)中就是定從,修飾限定the man)
BeiJin is a city (which has a long history).(括號(hào)中是定從,修飾the city)
狀語從句：在復(fù)合句中擔(dān)任狀語成分的從句叫狀語從句
例：I will tell her about that (when i see her).為時(shí)間狀從
just stay (where you are).為地點(diǎn)狀語
Because he is ill,he is absent today.為原因狀語
這也很局限,其實(shí)要講的還很多,你可以多看看語法書之類的