初中英语法大全：一般现在时一般现在时其结构按正常语序，即“主语+谓语+其它”，有时为了起强调作用，时间状语也可提前.其句式变化可分为两种情况1)表示动作，一般人称作主语的，变否定句须在动词前加助动词dont；变一般疑问句须在句首加助动词do。E.g.They have lunch at 12:00.They dont have lunch at 12:00.Do they have lunch at 12:00? 2）单三人称做主语的，变否定句须在动词前加助动词doesnt；变一般疑问句须在句首加助动词does。E.g.Jenny speaks English very well.Jenny doesnt speak English very well.Does Jenny speak English very well?含有be动词的要在be上做变化.E.g. Danny is a good student.Danny isnt a good student.Is Danny a good student?一般现在时：A一般现在时表示经常发生的习惯性的动作或目前所处的状态。We go to school every day.我们每天去学校。The students study very hard.学生们学习很努力。She has a dictionary.她有一本词典。在一般现在时句中，如果主语是第三人称时，动词要进行变化，变化规则如下：1)一般情况下，动词后面直接加-s.例如：works, gets, say, reads2)以ch,sh,s,x或o结尾的动词，在后面加-es。例如：goes, teaches, washes3)以辅音字母+ y结尾的动词，把y变为i再加-es.例如：studies, tries ,carries动词have遇有主语是第三人称单数时，have改为has。例如：He has an interesting book.他有一本有趣的书。Our classroom has two doors.我们的教室有两个门。一般现在时的具体用法：1)表示现在，目前存在的状态，性质或经常发生的动作或习惯。一般现在时常用下列副词或短语来做时间状语：often, usually, always, sometimes , seldom, every day(week, year, night), twice a month，on Sundays，never等副词连用。I often visit my teachers.我经常看望我的老师。They do morning exercises every day.他们每天做早操。2)表示按计划、规定要发生的动作（如己安排好的或计划好的动作），但限于少数动词，如：come, go, move, stop, leave, arrive,finish, continue, begin，start，return，open，close等。The train comes at 3 oclock.火车三点钟到。Tomorrow is Sunday.明天是星期天。Next week they leave for Shanghai.下周他们动身去上海。Our holidays begin in a week.一周后，我们的假期开始。3)在时间状语从句或条件状语从句中，一般现在时代替一般将来时。Ill help you as soon as you have problem.只要你有困难我就会帮助你。Tell Xiao Li about it if you meet him.如果你碰见小李，告诉他这件事情。If it doesnt rain tomorrow，well go to the Summer palace.如果明天不下雨，我们去颐和园。When he gets to the village，he will write to me.他到村里后就写信给我。4)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.汤姆把球带到左方。The picture shows us how they built the motorway last year.这张照片给我们展示了他们去年如何建设高速公路。5)客观真理，客观存在，科学事实。The earth moves around the sun.Shanghailies in the east ofChina.表示格言或警句中。Pride goes before a fall.骄者必败。注意：此用法如果出现在宾语从句中，即使主句是过去时，从句谓语也要用一般现在时。6)现在时刻的状态、能力、性格、个性。I dont want so much.Ann Wang writes good English but does not speak well.比较：Now I put the sugar in the cup.I am doing my homework now.第一句用一般现在时，用于操作演示或指导说明的示范性动作，表示言行的瞬间动作。再如：Now watch me, I switch on the current and stand back.第二句中的now是进行时的标志，表示正在进行的动作的客观状况，所以后句用一般现在时。7)有些表示心理状态或感情的动词（如be，like，hate，think，sound等）往往用一般现在时表示。I want your help.我需要你的帮助。I dont think you are right.我以为你错了。Most of the girls like flowers.8)其他Here comes Li Ming！李明来了There goes the bell！铃响了。Here he comes.他来了。学生常见错误如下：一、be动词与行为动词同时出现在句子中例：We are plant(plant) the trees in spring.答案：plant解析：学生往往会用汉语的思维方式去翻译，就成了“我们是在春天植树”。这是学习英语最忌讳的，要看语法是不是正确，在英语中，be是表状态，do是表动作，两种动词不能同时出现在句子中，可记住如下口诀：“英汉语言有差异，be、do不能放一起，仔细琢磨细分析，语法千万要牢记。”自我检测：(一)、单选1 Jenny _ in an office.Her parents _in a hospital.A work; worksB works; workCwork; are workingDis working; work2 One of the boys_ a black hat.A haveB there isC there areD has3 We will go shopping if it_ tomorrow.A dont rainBdidnt rainCdoesnt rainDisnt rain4 He said the sun _in the east and _in the west.A rose; setB rises; setsC rises, setD rise; sets5 Wang Mei _ music and often _ to music.A like; listenB likes; listensC like; are listeningD liking ; listen6 Jenny_ English every evening.A has studyB studiesC studyD studied答案：1 B2D3C4B5B6B(二)、填空1 I can take Li Ming there when he _( come) to visit.2 _your sister_(know)English?3Her home_(远离)her school.4The pot_(not look) like yours very much.5 Where _you_(have)lunch every day?6 Who_(想要)to go swimming?7 _she_(do) the housework every day?8 Jenny and Danny usually_(play) games in the afternoon .答案：1 comes2 Doesknow3 is away from4 doesnt look二、单三人称形式易出错例：1 He plaies (play) football very well.2 Danny gos (go) to school at 7:10.答案：1 plays2 goes解析：1以辅音字母加y结尾的动词变单三人称形式才能把y换成i再加es；2与名词变复数不同，变单三人称形式以o结尾的词要加es.三、在句式变换时易出错例：1 Does Jenny has (has) a good friend?2 Brian doesnt lives (not live) in China.答案：1 Doeshave2 doesnt live解析：单三人称做主语的一般现在时做句式变化时，可记住如下口诀：“见助动，用原形”。此口诀也可推广用于一般过去时态中。e.g. He didnt go home yesterday.四、对do的理解易出错例：We dont (not do) our homework in the afternoon.答案：dont do解析：do是一个比较难理解的词，它有三个含义:a)是所有行为动词的总称；b)是助动词，无实义；c)是一个具体的行为动词“做，干”。此句中给出的do指“做，干”，not指把此句变为否定句，故须在do前加助动词dont。五、对主语的数判断有误例：Li Ming with me are (be) inBeijing.答案: is解析:表面一看是“我和李明两个人在北京”，但with在此做伴随状语，不能做主语，故用is.