時(shí)間狀語從句是一個非常重要的語法項(xiàng)目，常見的用法主要有：
1.由when, while, as引導(dǎo)的時(shí)間狀語從句。
When you think you know nothing, then you begin to know something.當(dāng)你以為自己一無所知的時(shí)候，你就是在開始知道一些事物了。
When truth is buried under the ground it grows, it chokes, it gathers such an explosive force that on the day it bursts out , it blows up everything with it.當(dāng)真理被埋在地下的時(shí)候，它在生長，它感到壓抑，它蓄存著這么一種爆炸性力量，一旦冒出，它就會炸破一切！
Strike while the iron is hot. 趁熱打鐵。
Will you watch my clothes while I have a swim. 我游泳的時(shí)候，請你照看一下我的衣服。
You can feel the air moving as your hand pushes through it. 當(dāng)你的手在空氣中揮動的時(shí)候，你就能感覺到空氣在流動。
Our headmaster laughed as she spoke.我們的校長邊談邊笑。
注意：when, while和as的區(qū)別：when引導(dǎo)的從句的謂語動詞可以是延續(xù)性的動詞，又可以是瞬時(shí)動詞。并且when有時(shí)表示“就在那時(shí)”。
When she came in, I stopped eating.她進(jìn)來時(shí)，我在吃飯。
When I lived in the countryside, I used to carry some water for him.當(dāng)?shù)淖≡谵r(nóng)村時(shí)，我常常為他擔(dān)水。
We were about to leave when he came in.我們就要離開，就在那時(shí)他進(jìn)來了。
While引導(dǎo)的從句的謂語動作必須是延續(xù)性的，并強(qiáng)調(diào)主句和從句的動作同時(shí)發(fā)生（或者相對應(yīng)）。并且while有時(shí)還可以表示對比。
While my wife was reading the newspaper, I was watching TV. (was reading是延續(xù)性的動詞，was reading和was watching同時(shí)發(fā)生)
I like playing football while you like playing basketball.我喜歡踢足球，而你喜歡打籃球。
As表示“一邊……一邊”，as引導(dǎo)的動作是延續(xù)性的動作，一般用于主句和從句動作同時(shí)發(fā)生；as也可以強(qiáng)調(diào)“一先一后。
We always sing as we walk.我們總是邊走邊唱。
As we was going out, it began to snow.當(dāng)我們出門時(shí)，開始下雪了。（as強(qiáng)調(diào)句中兩個動作緊接著先后發(fā)生，而不強(qiáng)調(diào)開始下雪的特定時(shí)間）
2.由before和after引導(dǎo)的時(shí)間狀語從句。注意before引導(dǎo)的從句不再用否定式的謂語，并且當(dāng)before引導(dǎo)的從句位于主句之后，有時(shí)譯成“就，才”。還要注意主句和從句之間的時(shí)間關(guān)系。當(dāng)主句用將來時(shí)，從句總是用現(xiàn)在時(shí)；如果before引導(dǎo)的從句謂語用的是過去時(shí)，則主句動詞多用過去完成時(shí)，這樣以便體現(xiàn)動作發(fā)生的先后。After表示主句動作發(fā)生在從句動作之后。主句和從句的動作的時(shí)間關(guān)系正好與before引導(dǎo)的從句相反。如：
It will be four days before they come back. 他們要過四天才能回來。
Einstein almost knocked me down before he saw me.愛因斯坦幾乎把我撞倒才看到我。
My father had left for Canada just before the letter arrived.我父親恰好在信到之前去加拿大了。
They had not been married four months before they were divorced. 他們結(jié)婚還不到四個月就離婚了。
After you think it over, please let me know what you decide.你仔細(xì)考慮過以后，告訴我你是怎樣決定的。
After we had finished the work, we went home.完成工作之后，我們回家了。（從句用過去完成時(shí)，主句用一般過去時(shí)）
3.由till或until引導(dǎo)的時(shí)間狀語從句。till和until一般情況下兩者可以互換，但是在強(qiáng)調(diào)句型中多用until。并且要注意的是：如果主句中的謂語動詞是瞬時(shí)動詞時(shí)，必須用否定形式；如果主句中的謂語動詞是延續(xù)性動詞時(shí)，用肯定或否定形式都可以，但表達(dá)的意思不同。如：
I didn't go to bed until（till） my father came back.直到我父親回來我才上床睡覺。
It was not until the meeting was over that he began to teach me English.直到散會之后他才開始教我英語。
I worked until he came back.我工作到他回來為止。
I didn't work until he came back.他回來我這才開始工作。
Please wait until I arrived.在我到達(dá)之前請等我。
4.由since引導(dǎo)的時(shí)間狀語從句。 since引導(dǎo)的從句的謂語動詞可以是延續(xù)性的動詞，又可以是瞬時(shí)動詞。一般情況下，從句謂語動詞用一般過去時(shí)，而主句的謂語動詞用現(xiàn)在完成時(shí)。但在It is ＋時(shí)間＋since從句的句型中，主句多用一般現(xiàn)在時(shí)。
I have been in Beijing since you left. 自從你離開以來，我一直在北京了。
Where have you been since I last saw you? 自上次我和你見面以后，你到哪里去了？
It is four years since my sister lived in Beijing. 我妹妹不在北京住有四年了�！�
It is five months since our boss was in Beijing.我們老板離開北京有五個月了。
5.由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引導(dǎo)的時(shí)間狀語從句。這些連詞都表示“一……就”。
I will go there directly I have finished my breakfast. 吃完早飯，我立即到那里去。
The moment I heard the news, I hastened to the spot.我一聽到消息，馬上趕到了出事地點(diǎn)。
As soon as I reach Canada, I will ring you up. 我一到加拿大，就給你來電話。
注意：hardly(scarcely, rarely)…when / before, no sooner…than相當(dāng)于as soon as之意。主句用過去完成時(shí)，從句用一般過去時(shí)。當(dāng)hardly, scarcely, rarely和no sooner位于句首時(shí)，主句應(yīng)用倒裝語序。
He had no sooner arrived home than he was asked to start on another journey. 他剛到家，就被邀請開始另一旅程。
No sooner had the sun shown itself above the horizon than he got out of bed to commence work.太陽剛從地平線上升起，他就起床勞動去了。
Hardly had I sat down when he stepped in.我剛坐下，他就進(jìn)來了。
He had hardly fallen asleep when he felt a soft touch on his shoulder.這個阿拉伯人剛要入睡就感到肩膀上被輕輕一觸。
6.由by the time引導(dǎo)的時(shí)間狀語從句。注意時(shí)態(tài)的變化：在一般情況下，如果從句的謂語動詞用一般過去時(shí)，主句的謂語動詞用過去完成時(shí)；如果主句的謂語動詞用一般現(xiàn)在時(shí)，主句的謂語動詞用將來完成時(shí)。如：
By the time you came back, I had finished this book.到你回來時(shí)，我已經(jīng)寫完這本書了。
By the time you come here tomorrow, I will have finished this work. 你明天來這兒的時(shí)候，我將已經(jīng)完成此工作了。
7.由each time, every time和whenever引導(dǎo)的時(shí)間狀語從句。
Each time he came to Harbin, he would call on me. 他每次來哈爾濱，總是來看我。
Whenever that man says“To tell the truth”, I suspect that he's about to tell a lie.每當(dāng)那個人說“說實(shí)在話”的時(shí)候，我猜想他就要說謊了。
You grow younger every time I see you. 每次遇到你，見你更年輕了。
8.由as long as和so long as引導(dǎo)的時(shí)間狀語從句。這兩個連詞表示“有多久……就多久”。
You can go where you like as long as you get back before dark. 你可以隨意到哪里去，只要在天黑以前回來就行。
I will fight against these conditions as long as there is a breath in my body只要我一息尚存，我就要反對這種境況。
新疆哈密市紅星中學(xué)839000 王超