状语从句

when, as, while

when引出的時間狀語從句，其中的動詞既可以是延續性動作的動詞，也可以是瞬間性動作的動詞，而且可以表示主語的動作和從句的動作同時發生，或者從句的動作發生在主句的動作之前。
e.g.
  When you apply for a job, you must present your credentials.
  When the students heard the teacher's footsteps, they all stopped talking.
when還可以表示just then(正在那時，突然)的意思，此時其所引導的從句只放在主句之後。
e.g.
  We were about to start when it began to rain.
as引出的時間狀語從句，其動作是延續性的，而且側重表示主句和從句的動作同時發生.
e.g.
  As the students walked to their dormitories,they sang happily.
while表示"在某一段時間裡"或"在...期間"，其所引出的從句的動作是延續性的，且側重表示主句和從句的動作同時發生。
e.g.
  While the teacher paraphrased the text in English,the students listened attentively and took notes.
while還可用作並列連詞，相當於whereas，連接一個表示對比的並列分句。
e.g.
  Mary was dressed in blue while Jane was dressed in red.

whenever,every time,each time任何時候;每當

e.g.
  Whenever I met her,she was studying.
  Every time I met her,she was staying with him.
  Each time I met her,she was listening to the music.

since(自從，從...以來),ever since(從那時起一直到現在;此後一直)

since,ever since引導的從句通常用一般過去時，主句中的謂語動詞通常用完成時.
e.g.
  We've never met since we graduated from the college.
  It is six years since we parted.

before(在...之前),after(在...之後)

before引導的從句一般表示主句的動作發生在從句動作之前，如從句是過去時,主句一般用過去完成時.
e.g.
  I had written my dissertation before my supervisor went abroad.
after引導的從句，表示主句的動作發生在從句動作之後，如主句是過去時,從句一般用過去完成時.
e.g.
  After the boy had finished his homework,he played football with his friends.

till,until

until比較正式，可用於句首，而till一般不用於句首.till和until所表示的意義相同，但要注意以下情況:
如主句的謂語動詞是延續性動詞，就常用肯定式表示"直到...為止"
e.g.
  He will remain in college until(till) he finishes his Ph.D course.
如主句的謂語動詞是非延續性動詞，就常用否定式表示"直到...才"或"在...之前（不）".此時的till和still可用before替換，意義差別不大。
e.g.
  I won't go with you until(till) I finish my homework.

as soon as,immediately,directly,once,the minute/moment (that) etc.

as soon as,immediately,directly,once,the minute/moment (that)等引導的從句都表示從句的動作一發生，主句的動作隨即就發生，常譯為"一...就...".
e.g.
  As soon as we got home,the telephone rang.
  I recognized her immediately I saw her.
  Directly the teacher came in everyone was quiet.
  Once you understand this rule,you'll have no further difficulty.
  I want to see her the minute/moment (that) she arrives.

no sooner...than,hardly(scarcely)...when

no sooner...than,hardly(scarcely)...when引導的從句也表示"一...就","剛...就"的含義。但它們只用於過去時:主句中的動詞一般用過去完成時，從句用過去時.no sooner,hardly位於句首時，主句的謂語要部分倒裝.
e.g.
  He had no sooner arrived home than he was asked to start on another journey.
  No sooner had he arrived home than he was asked to start on another journey.
  No sooner had the words been spoken than he realized that he should have remained silent.
  Hardly had he reached the airport when the plane took off.

地點狀語從句

引導地點狀語從句的連詞有:where(在..地方),wherever(無論哪裡，在任何地方),everywhere(每一...地方，到處),anywhere（任何地方）.where總是放在主句後，絕不提前。
e.g.
  Where there is a will,there is a way.
  You can go wherever(anywhere) you like these days.
  Wherever (Everywhere) they went,they were warmly welcomed.
  I'll take you anywhere you like.

原因狀語從句

引導原因狀語從句的連詞有:because,as,since,for,now that,seeing that,considering (that),in that等。
e.g.
  I didn't go abroad with her because I couldn't afford it.
  Since traveling by air is much faster, they decided to take a plane.
  As it is snowing, we shall not climb the mountain.
  It must have rained last night, for the ground is wet.
  Now (that) you've passed your test, you can drive on your own.
  Seeing (that) the weather is bad, we'll stay at home.
  Considering (that) he's only been learning English a year, he speaks it very well.
  Advertisement is distinguished from other forms of communication in that the advertiser pays for the message to be delivered.
  I'm in a slightly awkward position, in that he's not arriving until 10th.

條件狀語從句

引導條件狀語從句的連詞或詞組:if（如果）,unless（除非）,as(so) long as（只要）,on condition that(條件是...),provided/providing that（假如）,suppose/supposing（假如）,in case（如果）,for fear(that/lest)(惟恐;以免),only if(只要;只有),if only(但願;要是...該多好)等。如果主句是將來時，條件狀語從句用一般現在時表示。

if,unless

unless的意義相當於"if...not"，而且語氣較強，一般不用於虛擬語氣.
e.g.
  I'll buy a computer if I am able to save up enough money.
  Unless the weather was bad,my father always used to take a walk in the evening.

suppose/supposing that,provided/providing (that)假如

e.g.
  Suppose you had a million pounds -- how would you spend it?
  Supposing (that) it rains,can we play the match indoors?
  I will agree to go provided/providing (that) my expenses are paid.

as(so) long as,on condition that,in case

as(so) long as(只要...就...),on condition that(在...條件下;倘若),in case(以防萬一，萬一，如果).
e.g.
  As long as you love me.
  As long as it doesn't rain,we can play.
  You can go out on condition that you wear an overcoat.
  You'd better take an umbrella in case it rains.

only if ,if only

only if引導真實條件句，用於句首，主語謂語倒裝.
e.g.
  Only if a teacher has given permission,is a student allowed to enter this room
if only一般引導虛擬條件狀語從句或感嘆句.
用一般過去式或would/could do表與現在或未來事實相反的願望；用過去完成時表與過去事實相反的願望，意為『但願』.
e.g.
  If only he had come,he would have met you.
  If only I could swim.

讓步狀語從句

讓步狀語從句的連詞或詞組有:although雖然，though雖然，even if/though即使;縱然;儘管，as儘管，while儘管，whoever(no matter who)不管誰，whatever(no matter what)無論什麼，whenever(no matter when)無論什麼時候，wherever(no matter where)無論哪裡，however(no matter how)無論怎樣，whether..or不論...還是。

although雖然though雖然even if/though即使;縱然;儘管

e.g.
  Although they have been talking for a long time,he cannot make her believe him.
  Though they lack offcial support,they continue their struggle.
  Though he is old,yet(still,nevertheless) he works day and night.
  Even if I failed again,I will not give up the experiment.
  I like her even though she can be annoying.

whatever(whoever,whichever,whenever...)/no matter what(who,which,when...)

e.g.
  Whoever(No matter who) wants to speek to me on the phone,tell them I'm busy.
  Wherever(No matter where) you go,I'm right here waiting for you.
  Whenever(No matter when) you call on us,you are welcome.

as雖然;儘管

as引導讓步狀語從句時，常放在作表語，狀語或謂語的一部分的形容詞，名詞，副詞或動詞原形之後。如果是單數名詞或形容詞的最高級作表語，不再用冠詞。
e.g.
  Strong as you may be,you cannot lift it.
  Late as it was,they continued to study.
  Youngest as he is in our class,he studies very well.
  Child as she is,She knows a lot.
  Hard as he tried,he was unable to make much progress.
  Much as I like you,I couldn't live with you.
  Much as I would like to stay,I really must go home.
  Call as you may,he will not come.
  Published as it was such a time,his work attracted much attention.

whether..or 不管;無論

e.g.
  Whether it rains or not, we're playing football on Sunday.
  Whether she is sick or well, she is always cheerful.

目的狀語從句

引導目的狀語從句的連詞或詞組一般有:so that以便，in order that以便，in case免得;以防，for fear(that)惟恐;以免，lest & for fear that惟恐;以免;為不使；now that & given that因為。
e.g.
  She wanted tea ready at seven so she could be by eight.
  They started early so that they might arrive in time.
  They stopped at Hangzhou in order that they could go around West Lake.
  She explained again and again in case we should misunderstand her.
  They spoke in whisper for fear (that) they might wake the baby.
  Lest anyone should think it strange,let me assure you that it is quite true.

結果狀語從句

結果狀語從句一般由so,that,so that,so...that,such that等引導放在主句之後。
e.g.
  He spoke so fast that nobody could understand what he was saying.
  He made such repid progress that he soon began to write articles in English.
  There is so little time left that I have to tell you about it later.
  He told us such a story that we all laughed.=He told us so funny a story that we all laughed.
  The shops were closed so I didn't get any milk.
  He phoned me on arrival so that I knew he was safe and sound.
  Suddenly it began to rain heavily,so that it was almost impossible to carry on driving.
注意：So that引導結果狀語從句時：so that前常有逗號，從句中常無情態動詞；引導目的狀語從句時：so that前常無逗號，從句中常有情態動詞。

方式狀語從句

方式狀語從句一般由連詞as(正如;就像),as if/though(好像;宛如)引導。

as引導的方式狀語從句，意思為"in the way or manner that"

e.g.
  Why didn't you catch the last bus as I told you to?
  She enjoys all kinds of music,as I do.
  Like me,she enjoys all kinds of music.
  Nobody understands him like/as I do.

as if/though

e.g.
  They looked at me as if/as though I were mad.
  They look as if/as though they know each other.

比較狀語從句

比較狀語從句一般由than（比）,as...as(和...一樣),not as/so...as...(和...不一樣),the+形容詞比較級/副詞比較級+the+形容詞比較級/副詞比較級(越...越...)等引導。

than

e.g.
  She likes reading better than (she likes) going to parties.
  He has lived here longer than I (has lived).
  They love the girl than (they love) him.
  He has more friends than she (does).
  Air in the country is much fresher than that in the city.
  She is younger than me.   <Spoken English>
  You are more industrious than her.   <Spoken English>

as..as 或 not so/as..as

e.g.
  We were as fortunate as them (they were).
  I hope she will make as much progress as you (have done).
  She runs as fast as a boy (does).

the...the...

e.g.
  The more you listen to English, the easier it becomes.
  The harder you work, the greater progress you will make.
  The more pictures I take,the more skilled I　become.