1).定語從句（The Attributive Clause）；
2).狀語從句（The Adverbial Clause）；
3).名詞性從句（The Noun Clause）
關係代詞有：who, whom, whose, that, which, as。
關係副詞有：when, where, why。 注意：關係副詞裡面沒有how。
I don’t like the way (that, in which) he eyed me.
He is the man who wants to see you.
He is the man who I saw in the park yesterday.
He is the man （whom） I saw in the park yesterday.
whose 用來指人或物，（只能用作定語, 若指物，它還可以同of which互換）。
They rushed over to help the man whose car had broken down.
Please pass me the book whose cover is green. （of which the cover/the cover of which）
They needed a plant which didn't need as much water as rice.
The farm (which) we visited yesterday is located in the suburb of Beijing.
I never met Julia again after that, which was a pity.
He can swim in the river, which I cannot.
4. 介詞 + which
They are all questions to which there are no answers.
It’s a question that (which) needs careful consideration.
Who is the man that is reading a magazine under the tree?
The girl (that) we saw yesterday is Tom’s sister.
1. 先行詞為all , everything, anything, nothing, little等不定代詞時。
All (that) she lacked was training.
This is the best film that I have ever seen.
3. 先行詞被序數詞和the last修飾時
They talked about the teachers and the schools that they had visited.
地點狀語從句通常由where, wherever 引導。
Where I live there are plenty of trees.
Wherever I am I will be thinking of you.
方式狀語從句通常由as, (just) as…so…, as if, as though引導。
1） as, (just) as…so…引導的方式狀語從句通常位於主句後，但在(just) as…so…結構中位於句首，這時as從句帶有比喻的含義，意思是"正如…"，"就像"，多用於正式文體，例如：
Always do to the others as you would be done by.
As water is to fish, so air is to man.
Just as we sweep our rooms, so we should sweep backward ideas from our minds.
2） as if, as though
They completely ignore these facts as if (as though) they never existed.
He looks as if (as though) he had been hit by lighting.
It looks as if the weather may pick up very soon.
說明：as if / as though也可以引導一個分詞短語、不定式短語或無動詞短語，例如：
He stared at me as if seeing me for first time.
He cleared his throat as if to say something.
比較：because, since, as和for
1） because語勢最強，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 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。
He is absent today, because / for he is ill.
He must be ill, for he is absent today.
表示目的狀語的從句可以由that, so that, in order that, in case等詞引導，例如：
You must speak louder so that /in order that you can be heard by all.
Better take more clothes in case the weather is cold.
結果狀語從句常由so… that 或 such…that引導，掌握這兩個句型，首先要了解so 和 such與其後的詞的搭配規律。
其規律由so與such的不同詞性決定。such 是形容詞，修飾名詞或名詞詞組，so 是副詞，只能修飾形容詞或副詞。 so 還可與表示數量的形容詞many, few, much, little連用，形成固定搭配。
so foolish such a fool
so nice a flower such a nice flower
so many / few flowerssuch nice flowers
so much / little money. such rapid progress
so many people such a lot of people
（ so many 已成固定搭配，a lot of 雖相當於 many，但 a lot of 為名詞性的，只能用such搭配。）
The boy is so young that he can't go to school.
He is such a young boy that he can't go to school
連線詞主要有 if, unless, as/so long as, on condition that 等。.
unless = if not.
Let's go out for a walk unless you are too tired.
If you are not too tied, let's go out for a walk.
注意： 當有though, although時，後面的從句不能有but，但是 though 和yet可連用
Although it's raining, they are still working in the field.
3) ever if, even though. 即使
We'll make a trip even though the weather is bad.
Whether you believe it or not, it is true.
5) "no matter +疑問詞" 或"疑問詞+後綴ever"
No matter what happened, he would not mind.
Whatever happened, he would not mind.
替換：no matter what = whatever
no matter who = whoever
no matter when = whenever
no matter where = wherever
no matter which = whichever
no matter how = however
注意：no matter 不能引導主語從句和賓語從句。
（錯）No matter what you say is of no use now.
（對）Whatever you say is of no use now.
你現在說什麼也沒用了。(Whatever you say是主語從句)
（錯）Prisoners have to eat no matter what they're given,
（對）Prisoners have to eat whatever they're given. 囚犯們只能給什麼吃什麼。
8 比較while, when, as
1）as, when 引導短暫性動作的動詞。
Just as / Just when / When I stopped my car, a man came up to me.
2）當從句的動作發生於主句動作之前，只能用when 引導這個從句，不可用as 或 while。
When you have finished your work, you may have a rest.
As the day went on, the weather got worse.
此兩個連詞意義相同。肯定形式表示的意思是"做某事直至某時"，動詞必須是延續性的。否定形式表達的意思是"直至某時才做某事"。動詞為延續性或非延續性都可 以。 正確使用這兩個連詞的關鍵之一就在於判斷句中的動詞該用肯定式還是否定式。
I slept until midnight. 我一直睡到半夜時醒了。
Wait till I call you.等著我叫你。
（在肯定句中可用before代替 Let's get in the wheat before the sun sets.）
She didn't arrive until 6 o'clock.
Don't get off the bus until it has stopped.
Until you told me, I had heard nothing of what happened.
2)Until when 疑問句中，until要放在句首。
---Until when are you staying? 你呆到什麼時候？
--- Until next Monday. 呆到下周一。
(1)Not until …在句首，主句用倒裝。
Not until the early years of the 19th century did man know what heat is.
Not until I began to work did I realize how much time I had wasted.
(2) It is not until… that…
hardly/scarcely…when/before, no sooner…than 和as soon as都可以表示"一…就…"的意思，例：
I had hardly / scarcely got home when it began to rain.
I had no sooner got home than it began to rain.
As soon as I got home, it began to rain.
注意：如果hardly, scarcely 或no sooner置於句首，句子必須用倒裝結構：
Hardly / Scarcely had I got home when it began to rain.
No sooner had I got home than it began to rain.
1）.賓語從句（The Object Clause）；
Everybody knows that money doesn't grow on trees.
Please go and find out when the train will arrive.
I am interested in what she is doing.
I don't suppose you're used to this diet.
I don't believe she'll arrive before 8.
2）.表語從句（The predicative Clause）；
What the police want to know is when you entered the room.
This is what we should do.
That's why I want you to work there.
as if, as though, because也可用來引導表語從句。
She seems as if she had done a great thing.
It is because you eat too much.
主語是idea, notion, proposal, suggestion, request等名詞時,作表語從句的動詞為原形動詞或should+原形動詞。
My suggestion is that we (should) go and help him.
Our only request is that this should be settled as soon as possible.
3）.同位語從句（The Appositive Clause）。
· 同位從句一般跟在某些名詞如answer(答案)，hope(希望)，fact(事實)，belief (信仰)，news(訊息)，idea(主意；觀念)，promise(承諾)，information(信息)，conclusion(結論)，order(命令)， suggestion(建議)，problem(問題)，thought (想法)等後面。例如：
I had no idea that you were here.
She told us her hope that she would become a pianist.
He made a promise that he would never come late.
He hasn’t made the decision whether he will go there.
I have small doubt whether he is suitable for the job.
I have no idea what he is doing now.
It’s a question how he did it.
whether, what, how可以用來引導同位語從句；而它們不能用來引導定語從句。