小学三四年级英语语法汇总一、陈述句定义:是用来陈述一件事情或表示一种看法，可分为肯定句和否定句两种形式。
1、谓语动词是be动词,助动词do/have/has,情态动词can等时，只要直接在这些词后面加not就构成否定形式。
eg. Lily has already read this new book. (改为否定句)Lily ______ ______ this new book ________.2、谓语动词是行为动词而又没有助动词或情态动词时，必须在谓语动词前加助动词，一般现在时加助动词do ，第三人称单数加does，一般过去时加did，再和not构成否定结构。
必须指出的是：don't, doesn't, didn't后都用动词原形。
eg.1)Jill has lunch at school every day. (改为否定句)Jill _____ _____ lunch at school every day.2)The children had a good time at the party. (改为否定句)The children ______ _____ a good time at the party.3)Rose didn't drink any milk this morning.（改为肯定句)Rose ______ ______ milk this morning.二、疑问句定义:是用来提出问题的句子。
A.一般疑问句：以be动词, have /has/do等助动词、can/may等情态动词开头，以yes或no 来回答的问句。
它的基本结构是：Be/Have/Has/Did等助动词（包括情态动词）＋主语＋谓语（包括表语）＋….？回答常用简略回答。
1、谓语动词是be动词、助动词、情态动词时，只要直接把这些词置于句首，句末改成问号。
eg. There's something wrong with his bike.（改成疑问句）______ _____ _______ wrong with his bike?2、谓语动词是行为动词时，必须在句首加上助动词Do、Does（三单）、Did（过去式）加上这些助动词后，句子中谓语动词必须用原形。
eg. 1)Edison built a science lab himself when he was ten. （改成疑问句）______ Edison ______ a science lab himself when he was ten？2)Those Japanese like Chinese food.（改成疑问句）______ those Japanese ________ Chinese food?注意：在把肯定句改成否定句或一般疑问句的时候,要注意句中是否有already、some、something、somebody等词，如果有也必须进行改变，already要改成yet，some、something、somebody等分别改成any、anything、anybody等。
另外，在改成否定句的时候注意把too 改成either,both改成neither,all改成none等.在改成一般疑问句的时候，常常把第一人称I、we改成第二人称you。
B.特殊疑问句：以疑问代词或疑问副词开头，提出疑问的句子。
它的基本结构是：特殊疑问词＋一般疑问句语序。
但是如果疑问词在句子中作主语或作主语的定语，就用特殊疑问词＋陈述句语序。
常用的疑问词有：what, who(whom), whose,which,when,where,how,why等，回答时针对问句中的代词和副词来回答，不用yes或no来回答。
1)对指物名词或谓语动词提出疑问，疑问词用what①The twins were making a kite when their mother came in. （划线提问）______ _____ the twins _____ when their mother came in?②Mrs Turner asked her son to buy some eggs for supper. （划线提问）_______ ______ Mrs Turner ask her son ______ _______?2)对名词前定语提出疑问，疑问词应用which，而且必须和名词连用。
I'm going to take the shirt on the right.（划线提问）______ _____ are you going to take?3)对指人名词或代词提问用who，作宾语时提问用whom。
4)对物主代词和名词所有格提问用whose。
5)对具体时间提出疑问，如in the morning,last Sunday等，疑问词用when；对具体几点钟提问，疑问词应用what time。
6)对具体地点提出疑问，疑问词应用where。
The pupils are having a picnic at the foot of the hill. （划线提问）_____ _____ the pupils having a picnic?7)对表原因的从句提问，常见的有because引导的从句，疑问词应用why。
Xiao Cheng didn't go to the farm with us because he was ill. （划线提问）_______ _____ Xiao Cheng go to the farm with us?8)对方式或程度等提出疑问，用疑问词How。
9)对数量提出疑问，疑问词为How many，要注意how many必须跟名词的复数形式。
eg. two hundred birds→How many birds10)对价格提出疑问，疑问词用How much。
eg. I paid fifty yuan for the sweater.______ ______ did you pay for the sweater?11)对时间长度提出疑问，疑问词应用How long。
eg. I've worked in that factory for two years. （划线提问）______ _____ _______ you worked in that factory?12)对时间频率，如once a year, twice a week等提问，疑问词用How often。
13)对具体次数，如once, twice, three times等提问，疑问词用How many times。
14)对in＋一段时间提问，疑问词一般用How soon。
eg. Jane and her brother will finish the work in two hours. （划线提问）_____ _____ _____ Jane and her brother finish the work?15)对距离提出疑问，疑问词用How far。
eg. It's about two kilometres from here to the country.（划线提问）______ _____ _____ _____ from here to the country?16)另外，对日期、星期、天气等提出疑问，则分别用What's the date?What day is it ? 如果是过去时间，就用was代替is。
What's the weather like?思考题1)The worker's visited the factory already.（改成否定句、一般疑问句）The worker _____ _____ the factory ______.____ the worker ___ the factory __?2)Both of his parents are workers.（改成否定句）___ of his parents ______ a worker.3)He went to the park with his sister.（划线提问）_____ ____ ____ he go to the park?4)We really enjoyed working on the farm.（划线提问）What _____ you really enjoy ______?5)She writes to her parents once a week.（划线提问）_______ ______ ______ she write to her parents?6)Our P.E teacher has been at this school since he came.（划线提问）______ ______ ______ our P.E teacher been at this school?三、时态1、一般现在时一般现在时的功能1).表示事物或人物的特征、状态。
如：The sky is blue.天空是蓝色的。
2).表示经常性或习惯性的动作。
如：I get up at six every day.我天天六点起床。
3).表示客观现实。
如：The earth goes around the sun.地球绕着太阳转。
一般现在时的构成：1). be动词：主语＋be(am,is,are)＋其它。
如：I am a boy.我是一个男孩。
2).行为动词：主语＋行为动词( 其它)。
如：We study English.我们学习英语。
当主语为第三人称单数(he, she,it)时，要在动词后加"-s"或"-es"。
如：Mary likes Chinese.玛丽喜欢汉语。
2、现在进行时(1)构成形式:Be动词+动词的ing形式注意:两者缺少其中任何一种都不可以构成现在进行时(2)现在进行时表示动作正在进行或事情正在发生(3)有用的依据:一个句子中既有be 动词，又有动词，且动词加了ing ,则该句是现在进行时(4)句中往往有now、look、listen 动词现在分词。