如何使用時(shí)間狀語從句

　　由since引導(dǎo)的時(shí)間狀語從句。

　　since引導(dǎo)的從句的謂語動(dòng)詞可以是延續(xù)性的動(dòng)詞，又可以是瞬時(shí)動(dòng)詞。一般情況下，從句謂語動(dòng)詞用一般過去時(shí)，而主句的謂語動(dòng)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)。例如：

　　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(gè)月了。

　　由as soon as, 等引導(dǎo)的時(shí)間狀語從句。

　　這些連詞都表示“一……就”。例如：

　　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。例如：

　　He had no sooner arrived home than he was asked to start on another journey. 他剛到家，就被邀請(qǐng)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(yáng)剛從地平線上升起，他就起床勞動(dòng)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(gè)阿拉伯人剛要入睡就感到肩膀上被輕輕一觸。

　　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(dòng)詞用一般過去時(shí)，主句的謂語動(dòng)詞用過去完成時(shí);如果從句的謂語動(dòng)詞用一般現(xiàn)在時(shí)，主句的謂語動(dòng)詞用將來完成時(shí)。例如：

　　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。

　　由each time, every time等引導(dǎo)的時(shí)間狀語從句。

　　例如：

　　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(gè)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。

　　由as long as和so long as引導(dǎo)的條件狀語從句。

　　這兩個(gè)連詞表示“只要“例如：

　　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(duì)這種境況。

　　一、when“當(dāng)……時(shí)”，引導(dǎo)時(shí)間狀語從句時(shí)，從句用于表示主句動(dòng)作發(fā)生的特定時(shí)間。如：

　　The days get longer when spring comes. = When spring comes, the days get longer.春天到來時(shí)，白天變得更長(zhǎng)了。

　　二、before“在……之前”，引導(dǎo)時(shí)間狀語從句時(shí)，表示主句動(dòng)作發(fā)生在從句動(dòng)作之前。如：

　　Close the door before you leave the room.離開房間前關(guān)上門。

　　三、after“在……之后”，引導(dǎo)時(shí)間狀語從句時(shí)，表示主句的動(dòng)作發(fā)生在從句的動(dòng)作之后。如：

　　I went to school after I finished my breakfast.吃完早飯后我就去上學(xué)了。

　　四、as soon as“一……就……”，引導(dǎo)時(shí)間狀語從句時(shí)，表示主句動(dòng)作緊接著從句動(dòng)作發(fā)生。如：

　　I’ll call you as soon as I get home.我一到家就給你打電話。

　　五、until, till“直到”，引導(dǎo)時(shí)間狀語從句。當(dāng)主句謂語動(dòng)詞是延續(xù)性動(dòng)詞時(shí)，主句常用肯定形式;當(dāng)主句謂語動(dòng)詞是非延續(xù)性動(dòng)詞時(shí)，主句要用否定形式，即“not…until/till…”意為“直到……才……”。如：

　　I’ll wait here until/till the rain stops.我將在這里等著，直到雨停。

　　You can’t go home until/till you finish your work.直到你完成你的工作，你才能回家。