很多同學(xué)在大學(xué)英語四級(jí)考試中會(huì)存在一些誤區(qū)，認(rèn)為語法不那么重要，其實(shí)英語語法是學(xué)習(xí)英語的指南，也會(huì)為我們大大地提高英語，以下是小編給大家整理的大學(xué)英語四級(jí)考試語法基礎(chǔ)：時(shí)態(tài)，希望可以幫到大家
1. 現(xiàn)在完成時(shí)、過去完成時(shí)以及將來完成時(shí)之間的區(qū)別
1) 現(xiàn)在完成時(shí)：
① 構(gòu)成：have / has +過去分詞
② 語法意義及要點(diǎn)：
a. 現(xiàn)在完成時(shí)表示一個(gè)過去開始的狀態(tài)或動(dòng)作持續(xù)到現(xiàn)在并可能繼續(xù)持續(xù)下去，常同表示一段時(shí)間的狀語連用。如so far， up to now， since， for a long time等。
--he has worked as a teacher for many years.
--up till now， nothing has gone wrong.
b. 現(xiàn)在完成時(shí)表示一個(gè)過去發(fā)生的對(duì)現(xiàn)在仍有影響的動(dòng)作或事件。常與不確定的過去時(shí)間狀語連用，如yet， just， before， recently等;也同表示頻度時(shí)間狀語連用，如often， ever， never， sometimes， several times等;還可同包括現(xiàn)在時(shí)間在內(nèi)的時(shí)間狀語連用，如now， today， this morning等。但不能同特定的過去時(shí)間狀語連用(last year ， in 1997等)。
--i have never learned japanese before.
--we have been quite busy lately (recently)。
c. 在時(shí)間或條件狀語從句中，當(dāng)表示將來完成時(shí)的意義時(shí)，要用現(xiàn)在完成時(shí)來代替將來完成時(shí)。
--we’ll start at 5 o’clock if it has stopped raining by then.
--i shall go to see you when i have finished my homework.
note： 行為不能持續(xù)的瞬間動(dòng)詞(instantaneous verb)， 如arrive， begin， come， go， start， leave， die， join等通常不能用于這一語法意義，即該類動(dòng)詞在現(xiàn)在完成時(shí)中不能與表示一段時(shí)間的狀語連用。
--he has joined the army for five years. (誤)
--he has been in the army for five years. (正)
2) 過去完成時(shí)：
① 構(gòu)成：had +過去分詞
② 語法意義及要點(diǎn)：
過去完成時(shí)表示某一動(dòng)作或情況發(fā)生在過去某一時(shí)刻之前并持續(xù)到該時(shí)刻。
--david and jenny had known each other for a long time before their marriage.
--they had got everything ready before the party began.
note： 與現(xiàn)在完成時(shí)截然不同的是過去完成時(shí)可以與表示具體過去的時(shí)間狀語連用。
--he said that he had seen her the day before yesterday.
3) 將來完成時(shí)：
① 構(gòu)成：shall / will + have +過去分詞
② 語法意義及要點(diǎn)：
將來完成時(shí)表示某一動(dòng)作在將來某一時(shí)刻或?qū)砟骋粍?dòng)作之前已經(jīng)完成或發(fā)生。
--he will have graduated from high school before his next birthday.
--the shop will have closed already before you get there.
2. 哪些動(dòng)詞不能用于進(jìn)行時(shí)
1) 表示狀態(tài)的動(dòng)詞，如be， seem， appear， become， get等。
he is being a used-car dealer.(誤)
he is a used-car dealer.(正)
she is seeming always about to smile.(誤)
she seems always about to smile.(正)
2) 表示感官感覺的動(dòng)詞，如see(看見)， hear(聽見)，feel(感覺出)， taste(嘗出)，smell(聞到)等。
the medicine is tasting bitter. (誤)
the medicine tastes bitter. (正)
i was seeing a car passing by our house. (誤)
i saw a car passing by our house. (正)
3) 表示擁有的動(dòng)詞，如have， own， possess， belong， contain， hold等。
he is owning a luxurious car. (誤)
he owns a luxurious car. (正)
the book is belonging to her. (誤)
the book belongs to her.(正)
4) 表示思想狀況、態(tài)度的動(dòng)詞，如believe， think， know， understand， agree， approve， consider， expect， forget， guess， hesitate， hope， imagine， mean， realize， remember， suppose， trust， want， wish等。
i’m thinking that he is right. (誤)
i think that he is right. (正)
i’m understanding your feelings. (誤)
i understand your feelings. (正)
5) 表示情感、愿望的動(dòng)詞，如admire， appreciate， care， enjoy， like， love， hate， detest， regret等。
he is loving his daughter very much. (誤)
he loves his daughter very much. (正)
i’m regretting to say we cannot come. (誤)
i regret to say we cannot come. (正)
3. 時(shí)態(tài)的呼應(yīng)
時(shí)態(tài)的呼應(yīng)又稱時(shí)態(tài)一致(sequence of tenses)，指的是某些從句里的動(dòng)詞謂語時(shí)態(tài)必須和主句里的時(shí)態(tài)保持一致。
如果主句里的謂語動(dòng)詞是過去時(shí)態(tài)(過去時(shí)或過去完成時(shí))，那么從句的謂語動(dòng)詞時(shí)態(tài)也相應(yīng)地要用過去時(shí)。時(shí)態(tài)的呼應(yīng)主要發(fā)生在間接引語和賓語從句中，但其他從句有時(shí)也存在時(shí)態(tài)一致的問題。
--he explained that he had learned chinese for many years.(現(xiàn)在完成時(shí)變?yōu)檫^去完成時(shí))
--he said he had been collecting materials on that subject for a long time.(過去進(jìn)行時(shí)變?yōu)檫^去完成進(jìn)行時(shí))
--he told me that they would have completed that project by the end of the year.(將來完成時(shí)變?yōu)檫^去將來完成時(shí))
雖然主句用了過去時(shí)等，如果從句表示的是科學(xué)真理、客觀事實(shí)或某人(物)的經(jīng)常性特點(diǎn)時(shí)，其時(shí)態(tài)可以不必遵守時(shí)態(tài)呼應(yīng)的規(guī)則而仍用一般現(xiàn)在時(shí)。
--galileo proved that the earth revolves round the sun.
--the teacher told the students that knowledge is power.
如果從句中有一個(gè)表示絕對(duì)過去時(shí)間的狀語，就不必把一般過去時(shí)變?yōu)檫^去完成時(shí)。
--he said that he joined the red army in 1933.
