2020届高考英语语法专题复习ampnbsp语法剖析三种时态

　　语法剖析---三种时态
　　一般现在时 谓语形式 (1)谓语是系动词be。 (2)谓语是行为动词。 一般现在时句中，如果主语是第三人称时，动词要进行变化： ①一般情况下，动词后面直接加-s。例如：works,gets,says,reads ②以ch,sh,s,x或o结尾的动词，在后面加-es。例如：goes,teaches,wases ③以辅音字母+y结尾的动词，把y变为i再加-es。例如：studies,tries,carries 用法
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　　例句表示经常性、习惯性的动作及现在存在的特征或状态；常与表示频度的时间状语连用。she is often late for school. i leave home for school at 7 every morning.表示客观规律、正确事实或科学真理、格言及客观存在。the earth moves around the sun.failure is the mother of success. all the living things on the earth depend on the sun.表示主语现在的状态、能力、性格或个性。the boy is always ready to help others.he writes good english but does not speak well.表示计划或安排要做的动作（有时间状语）,限于begin,come,leave,go,arrive,start,move,stop,open,close,return等一类动词。the plane takes off at ten o’clock. they leave for shanghai next sunday. the film starts at eight o’clock this evening.在有连词if,unless,before,when,as soon as,once,however等引起的时间（条件、让步）状语从句,需用一般现在时表示将来。if you work hard,you’ll succeed in passing the exam. we’ll go out for a walk as soon as the rain stops.一般现在时还可用在戏剧、电影的剧本解说、体育比赛的解说以及图片的说明等场合。tom carries the ball to the left. the picture shows us how they built the motorwaylast year.
　　现在进行时 构成：动词原形-ing (1)一般情况在动词原形后加-ing。例如：go—going,stand—standing (2)以不发音的e结尾的动词，去掉e,再加-ing。例如：arrive—arriving (3)少数几个以-ie结尾的动词，须将ie变成y,再加-ing。例如：die—dying　lie—lying(4)以元音+辅音结尾的重读闭音节，双写辅音字母，再加-ing。例如：stop—stopping 用法
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　　例句表示现在（指说话人说话时）正在发生的事情。tom is playing basketball now. we are waiting for you.表示目前一段时间内正在进行的动作,说话时动作未必正在进行。mr green is writing another novel. she is learning piano under mr smith.与always,constantly,forever 等词连用,表示反复发生的动作或持续存在的状态,往往带有说话人的主观色彩,如赞叹或厌恶等。she is always changing her mind.（表示厌烦）you should not be constantly making the same mistake.表示在最近计划或安排要进行的动作。常限于go,come,leave,start,arrive,return,stay,do,have,wear等表移动、方向的词。we are starting the work in a few days. my friends are coming to see me tomorrow.the plane is taking off in a few minutes.
　　一般将来时
　　构成
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　　例句shall/will+动词原形表示单纯的将来；必然的将来；表示意愿、决心we shall know more and more as time goes on.no one knows what will happen in the future.i will explain it once again if you listen to me.be going to +动词原形表示计划、打算；表示客观迹象what are you going to be in the future?look! the clouds are gathering.it is going to rain.be about to + 动词原形表示即将或正要去做……,不与时间状语连用, 但可和when 从句连用。i am about to go to the cinema.the train is about to leave.be to + 动词 原形表示预定要做……；（表命令、禁止）应该……all these are to be answered for!you are not to smoke in the meeting-room.be doing表示按计划安排即将发生的动,常限用于go,come,start,leave,reach,arrive,return,move等位移动词。they are leaving for shanghai next week.when are you going abroad?