【正文】 。并且while有時還可以表示對比。例如：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同時發(fā)生)I like playing football while you like playing ，而你喜歡打籃球。（對比）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發(fā)生；as也可以強調(diào)“一先一后。例如：We always sing as we 。（as表示“一邊……一邊”）As we was going out, it began to ，開始下雪了。（as強調(diào)句中兩個動作緊接著先后發(fā)生，而不強調(diào)開始下雪的特定時間）。注意before引導(dǎo)的從句不再用否定式的謂語，并且當before引導(dǎo)的從句位于主句之后，有時譯成“就，才”。還要注意主句和從句之間的時間關(guān)系。當主句用將來時，從句總是用現(xiàn)在時；如果before引導(dǎo)的從句謂語用的是過去時，則主句動詞多用過去完成時，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間關(guān)系正好與before引導(dǎo)的從句相反。例如：It will be four days before they e 。Einstein almost knocked me down before he saw 。My father had left for Canada just before the letter 。They had not been married four months before they were 。After you think it over, please let me know what you ，告訴我你是怎樣決定的。After we had finished the work, we went ，我們回家了。（從句用過去完成時，主句用一般過去時）。till和until一般情況下兩者可以互換，但是在強調(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動詞時，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，用肯定或否定形式都可以，但表達的意思不同。例如：I didn39。t go to bed until（till）my father came 。It was not until the meeting was over that he began to teach me 。I worked until he came 。I didn39。t work until he came 。Please wait until I 。since引導(dǎo)的從句的謂語動詞可以是延續(xù)性的動詞，又可以是瞬時動詞。一般情況下，從句謂語動詞用一般過去時，而主句的謂語動詞用現(xiàn)在完成時。但在It is ＋時間＋since從句的句型中，主句多用一般現(xiàn)在時。例如：I have been in Beijing since you ，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 。It is five months since our boss was in 。 soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引導(dǎo)的時間狀語從句。這些連詞都表示“一……就”。例如：I will go there directly I have finished my ，我立即到那里去。The moment I heard the news, I hastened to the ，馬上趕到了出事地點。As soon as I reach Canada, I will ring you ，就給你來電話?！咀⒁狻縣ardly(scarcely, rarely)…when / before, no sooner…than相當于as soon as之意。主句用過去完成時，從句用一般過去時。當hardly, scarcely, rarely和no sooner位于句首時，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 ，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 mence ，他就起床勞動去了。Hardly had I sat down when he stepped ，他就進來了。He had hardly fallen asleep when he felt a soft touch on his 。 the time引導(dǎo)的時間狀語從句。注意時態(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，主句的謂語動詞用過去完成時；如果主句的謂語動詞用一般現(xiàn)在時，主句的謂語動詞用將來完成時。例如：By the time you came back, I had finished this ，我已經(jīng)寫完這本書了。By the time you e here tomorrow, I will have finished this ，我將已經(jīng)完成此工作了。 time, every time和whenever引導(dǎo)的時間狀語從句。例如：Each time he came to Harbin, he would call on ，總是來看我。Whenever that man says“To tell the truth”, I suspect that he39。s about to tell a “說實在話”的時候，我猜想他就要說謊了。You grow younger every time I see ，見你更年輕了。 long as和so long as引導(dǎo)的時間狀語從句。這兩個連詞表示“有多久……就多久”。例如：You can go where you like as long as you get back before ，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。三 地點狀語從句167。4地點狀語從句(adverbial clause of place)地點狀語從句一般由連接副詞where, wherever等引導(dǎo)，已經(jīng)形成了固定的句型，例如：句型1：Where＋地點從句，（there）＋主句?！咀⒁狻看司湫屯ǔＷg成“哪里……哪里就……”；主句在從句后面時，there可用可不用；如果主句在從句的前面時，一般都不用there。例如：Where there is no rain, farming is difficult or ，耕作是困難的，或根本不可能的。They were good they went, there they were warmly 。因此他們走到哪里都受到熱烈歡迎。You should have put the book where you found 。Where the Communist Party of China goes, there the people are ，哪里人民得解放。句型2：Anywhere/ wherever＋地點從句，＋主句?！咀⒁狻縜nywhere本身是個副詞，但是，?？梢砸龑?dǎo)從句，相當于連詞，意思相似于wherever, anywhere引導(dǎo)的從句可位于主句之前，也可以位于主句之后。而wherever本身就是個連詞，表示“在何處，無論何處”。例如：Wherever the sea is , you will find 同位語一個名詞(或其它形式)對另一個名詞或代詞進行修飾，限定或說明，這個名詞(或其它形式)就是同位語。同位語與被它限定的詞的格要一致，并常常緊挨在一起。,其中前項與后項所指相同,句法功能也相同,后項是前項的同位語。, our new teacher, is very kind to 。 new teacher的同位語,指同一人。Yesterday I met Tom, a friend of my brother39。a friend of my brother39。s是受詞Tom的同位語,指同一人。如同位語對其同位成分只作補充解釋時可用逗點隔開。He himself told me that his brother John is a worldfamous ,他的兄長約翰是一位世界聞名的醫(yī)生。himself和John都是單一的字作同位語,與其同位成分之間不用逗點隔開。Yesterday I talked to my English teacher, 。 English teacher,同位語與其同位成分之間可用逗點隔開。,還可以表示部分意義。We Chinese people are brave and 。He is interested in sports, especially ball ,特別是球類運動。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(消息)，idea(主意；觀念)，promise(承諾)，information(信息)，conclusion(結(jié)論)，order(命令)，suggestion(建議)，problem(問題)，thought(想法)等后面。例如： He always works hard even if he knows the fact that he is not in good failure was due to the fact that he had not practised for a long had no idea that you were told us her hope that she would bee a made a promise that he would never e ： that 既可引導(dǎo)同位語從句又可引導(dǎo)定語從句，其區(qū)別在于：同位語從句由連接詞that引導(dǎo)，連接詞that本身無意義，在同位語從句中不充當任何成分，不可省略，不可以用其他詞替代；定語從句由關(guān)系代詞that引導(dǎo)，關(guān)系代詞that在從句中充當一定的成分，作賓語時可省略，由when, why, where引導(dǎo)的 同位語從句和定語從句的區(qū)別在于： 同位語從句由連接副詞只起連接作用，沒有指代作用； 定語從句由關(guān)系副詞引導(dǎo)，關(guān)系副詞具有指代先行詞的作用，常用一個介詞加關(guān)系代詞替換。例如:I will never forget the day when we first met.（同位語從句, when為連接詞）That is the special day(which/that)I will never forget.（定語從句，which/that為關(guān)系副詞）This is the house where we lived fifteen years ago.（同位語從句, where為連接詞）This is the house which we sold fifteen years ago.（定語從句，where為關(guān)系副詞）區(qū)分表語從句和同位語從句從句是相對于主句而言的，即它是從屬于某一個主句，而不能單獨作一個句子。在英語中，主要有三大從句，即名詞性從句（包括主語從句，賓語從句，表語從句，同位語從句）、形容詞性從句（即定語從句）、副詞性從句（即狀語從句,包括時間、條件、結(jié)果、目的、原因、讓步、地點、方式等）。主語從句用作主語，如：：That the earth is round is 。賓語從句用作賓語。如：Do you know where he lives?表語從句用作表語，如：My opinion is that you should not go 。同位語從句用于解釋說明前面的名詞。如：The fact that the earth is round is 。（that從句用于解釋說明the fact）定語從句相當于一個形容詞，用于修飾前面的名詞。如：The student who answered the question was ，如：When it rains, I usually go to school by ，我通常坐公共汽車上學(xué)。（時間狀語）If he es tomorrow, you will see ，你就可以看見他。（if 引導(dǎo)的條件狀語從句，其結(jié)構(gòu)為：if +狀語從句，＋主句）。要注意在狀語從句中有一個規(guī)則是“主將從現(xiàn)”，即主句是將來時，則從句要用一般現(xiàn)在時表示將來。主句和從句的劃分方法是相同的。句子的成分從謂語動詞處來劃分比較容易。謂語動詞前面的部分是主語，后面常接賓語，修飾謂語動詞的是狀語，修飾主語、賓語的是定語，若謂語是系動詞，則系動詞后的部分是表語。如：I am a ，I 是主語，am是謂語，a teacher 是表語。He likes playing football very ，he是主語，likes是謂語，playing football是賓語，very much是狀語。參考資料：