A. before用法 問題： before的用法有哪些
prep. 在......以前，強調時間
He came to see me the day before yesterday. 他前天來看我了。
2. prep. 在......前面，當著......的面，向......，強調地點
She has to appear before the court. 她必須出庭受審。
3. prep. 在......之前，先於，強調次序
Those with babies can get on the bus before others. 帶小孩的人可以先上汽車。
4. prep. 與其......（寧願）
I'd shoot myself before I apologized to him! 我寧死也不向他道歉!
5. adv. 以前，強調時間
We've seen that film before. 我們以前看過那場電影。
6. adv. 在前面，向前，強調位置
Don't run before and after. 別跑前跑後。
7. conj. 在......前，強調時間
before的含義比較靈活，實際翻譯時應結合具體情況機動處理。
趁......
You should do it before it is too late. 趁現在還不算太晚，你應該趕快做它。
2. 尚未來得及
Before she could move, she heard a loud noise, which grew to a terrible roar. 她還沒有來得及動彈，就聽見有很響的聲音，接著就成了可怕的隆隆轟鳴聲。
Before they reached the house, a new great wave came, sweeping down trees, and sweeping them down too. 他們還沒到屋子，又一個巨浪打來，沖倒了樹，也沖倒了他們。
3. 要......先......
You should be a pupil before you become a teacher. 要當老師，先作學生。
二、掌握熱點句型用法
It was not long before...（過去）沒過多久就......
It was not long before he returned to Beijing. 不久他就回到北京。
需要特別注意，該句型可以進行創新，可將否定句改為肯定句（It was long before...過了很久才......）或將一般過去時改為一般將來時（It will not be long before...要不了多久就......；It will be long before...要過很久才......）。before在這些句型中均引導時間狀語從句， long這個抽象的時間也可改為years, weeks, days等具體表時間的詞。
It was long before he married Wei Fang. 過了很久他才娶魏芳。
It will be long before he goes abroad. 要過很久他才出國。
Will it be years before he goes to school? 要過好幾年他才能上學嗎？
since的用法：譯作「自從…以來」
(1)接時間點：如 I have stayed in that country since 1995.要求：謂v.用現在完成時,而且須是延續性動詞.
(2)接一段時間 + ago：如 They have lived in that house since two years ago.
要求：謂v.用現在完成時,而且須是延續性動詞.
(3)接時間狀語從句：如 I have loved her since I met her last time./ Lily has stayed at home since she left school.
要求：主句的謂v.用現在完成時,而且須是延續性動詞；從句的謂v.用一般過去時,而且須是終止性動詞.
(4)用於句型「It』s / It has been + 一段時間 + since + 時間狀語從句」中,譯作「自從…以來,已經…(時間)了」.
如 It』s / has been three months since he moved to this city.
要求：主句的謂v.用一般現在時或現在完成時；從句的謂v.用一般過去時,而且須是終止性動詞.
(5)用於句型「一段時間 + has passed since + 時間狀語從句」中,譯作「自從…以來,…
(時間)已經過去了」.
如上個例句還可寫成：Three months has passed since he moved to this city
.要求：主句的謂v.用現在完成時,而且動詞必須是has passed；從句的謂v.用一般過去時,而且須是終止性動詞.
(6)註：當since用於否定句時,主句的謂v.可以是終止性動詞.
如 He hasn』t seen the film since last month.
(7)相關片語：「從那時起」：ever since、since then、from then on.
註：ever since作為一個片語,放句尾可單獨使用.
如I have given up smoking ever since.另外,還可在since後接句子.since前加ever,只是加重語氣而已.
如 I have given up smoking ever since I caught a bad cough.
(8) since還可引導原因狀語從句,譯作「由於；因為」,相當於because.
如 Since he was lazy,he didn』t finish his homework.
that 用法
pron.
1.那;那個,那人,那事,那東西
That's my English teacher over there.
那邊是我的英文老師.
2.(已被提到的)那個,那人,那事,那東西
Who told her that?
那是誰告訴她那件事的?
3.前者
4.(用作關系代詞的先行詞)那,那個
What is that which you have just stuffed into the plastic cup?
你剛才塞在塑料杯里的是什麼東西?
5.(代替句中名詞,避免重復)
The output of steel this year has increased by 20% compared with that in 1992.
今年鋼產量比一九九二年增長了百分之二十.
6.(用作關系代詞,引導關系從句)
a.
1.那,那個
That book isn't mine.
那本書不是我的.
ad.
1.【口】那樣,那麼
Is the problem that easy?
問題有那麼簡單嗎?
conj.
1.(引導名詞從句)
He expressed the hope that we would keep in touch with his firm.
他表示希望我們與他的公司保持聯系.
My idea is that we should act on his suggestion.
我的意見是我們應當按照他的建議去辦.
That she is still alive is a relief.
她還活著,這是令人感到寬慰的.
2.(引導狀語從句,表示原因或理由)因為,由於
We are glad that we have accomplished another arous task.
我們都感到高興因為又完成了一項艱巨的任務.
3.(引導狀語從句,表示目的或結果)為了,以至於
He is working hard that he can catch up with the class.
他努力用功,以便趕上班上同學.
4.(引導表示願望,感嘆的從句,主句常省略)
That I could stay at home today!
今天要是我能呆在家裡多好呀!
after
1介詞:
(a) Please come to my house after dinner.晚飯後
(b) He ran after the bus.追趕
(c) His mother waited for him night after night.（一個）接著（一個）
(d) It's sad to fail after all that work.由於
(e) They are still friends after all their differences.
2 副詞:
(a) three hours after; (b) departed shortly after; (c) after all I don't really know him.終究
(d) He told me afterwards that he had not enjoyed the film.後來
3連詞:
(a) I saw them after I arrived.後來
(b) They arrived soon after.後來
(c) tomorrow,or the day after...
4 名詞:
(a) afternoon午後; (b) afterthought事後的想法; (c) aftermath後果
一 .when 用作副詞.
1.用作疑問副詞,引導特殊疑問句.例如：
When will you come to see me?你什麼時候要來看我?
When are they going to visit the Great Wall?他們打算什麼時候去游覽長城?
2.用作連接副詞,通常用來引導主語從句、表語從句、同位語從句、賓語從句及起名詞作用的「 when ＋動詞不定式」結構.例如：
When he comes is not known.他何時來還不知道.
The morning is when I am busiest.早上是我最忙的時候.
I have no idea when the game will begin.我不知道比賽何時開始.
I don't know when the plane takes off.我不知道飛機何時起飛.
I don't know when to leave for London.我不知道該在何時動身去倫敦.
3.用作關系副詞,引導限定性定語從句和非限定性定語從句.例如：
Do you still remember the days when we stayed in America?你還記得我們呆在美國的那些日子嗎?
The day will come soon when the Chinese astronauts will go to the moon.中國宇航員登上月球的那一天很快就要到來了.
It happened ten years ago,when I was a child.事情發生在十年前,當時我還是個小孩子.
We will go to the countryside at the beginning of June,when the summer harvest will start.我們將在六月初下鄉,那時夏收就要開始了.
二 .when 用作連詞.
1.用作從屬連詞,意為「當……的時候」,引導時間狀語從句.例如：
They learned a lot from the peasants when they stayed in the village.
他們住在那個村子時,從農民那裡學到了許多東西.
It was snowing when he arrived at the station.他到達車站時,天正下著雪.
注意：如果 when 引導的從句中的主語和主句中的主語一致,且從句中的謂語動詞是「 be ＋分詞」或從句主語是 it ,則 be 動詞及其主語常可省略.例如：
When （ he was ） asked why he was late,he made no answer.當被問到他為什麼遲到時,他避而不答.
I'll tell him about it when （ it is ） possible.在可能的時候,我會把那件事告訴他的.
2.用作從屬連詞,意為「一……就……」,引導時間狀語從句.例如：
We will stand up when the teacher comes into the classroom.老師一進教室我們就起立.
Fire the rockets when I give the signal.我一發信號,你就點燃火箭.
3.用作從屬連詞,意為「還沒 / 剛剛……就」,引導時間狀語從句.例如：
I had hardly opened the door when he came in.我剛一開門,他就進來了.
I had not been reading for half an hour when I heard someone call my name.我剛剛看了半個小時的書,就聽到有人叫我的名字.
4.用作從屬連詞,意為「倘若,如果」,表示條件.例如：
He will be likely to recover when he is operated on.如果動手術,他有可能康復.
Turn off the switch when anything goes wrong with the machine.如果機器發生故障,就把電源關上.
5.用作從屬連詞,意為「既然,盡管」,表示讓步.例如：
Why use metal when you can use plastic?既然能用塑料,為什麼用金屬呢?
They kept trying when they knew it was hopeless.盡管他們知道那件事沒有希望,可是他們還在不斷地努力.
6.用作並列連詞,意為「在那時,屆時」,表示時間.這時主句中可以用過去進行時,過去完成時或「 was/were about to do sth.」結構.例如：
Last night I was about to go to bed when the phone rang.昨天晚上我正要上床睡覺時,電話鈴響了.
I was cooking in the kitchen when someone knocked at the door.我正在廚房做飯,這時有人敲門.
He had just finished the book when supper was served.我剛剛讀完這本書,這時晚飯就端上來了.
7.用作並列連詞,意為「雖然、然而、可是」,表示轉折.例如：
He usually walks to work when he might take a bus.雖然他可以坐公共汽車上班,但他卻常常步行上班.
I had only twenty dollars when I needed thirty to buy the dictionary.
我需要 30 美元買那本字典,可是我只有 20 美元.
8.用作並列連詞,意為「而、卻」,表示對比.例如：
How can he say that everything is fine when it's obvious that it is not?他怎能說一切都好呢?情況顯然不是那樣.
三 .when 用作代詞.
when 作為代詞常常位於介詞之後,意為「那時,什麼時候」.例如：
We came back on Tuesday,since when we have been working in the repair shop.我們星期二回來,從那時起就一直在修配車間工作.
Since when have you been studying Japanese?你是從何時起一直學習日語的?
另外,when 還可用作名詞,前面常常用定冠詞 the .the when 表示事件發生的時間,常常與 the where,the how 並列使用.例如：
He told the police the when and the how of the accident.他告訴警察事故發生的時間及發生的原委.