一般现在时专题讲解1．概念：一般现在时表示经常的、习惯性的动作或存在的状态一般现在时表示现在经常反复发生的动作、存在的状态或习惯性的动作的时态。
可概括为①经常性或习惯性动作；②长期存在的特征或状态；③普遍真理、客观事实等。
2．构成：一般现在时的构成主要有两种形式,一般现在时用行为动词的原形，但第三人称单数作主语时，动词的词尾要加-S。
：（1）be型：句子的谓语动词只有be（am，is或are）：a．肯定句中，只出现be，如：I am a student．我是一名学生。
b．否定句中，要在be后面加not，如：She isn't a teacher．她不是教师。
c．一般疑问句，要将be放在句子开头（注意句首字母大写），句尾用问号，答语用Yes，主语+be．或No，主语+be+not．如：—Are you ready？—你准备好了吗？—Yes，I am．—是的，我准备好了。
（—No，I'm not．—不，我没准备好。
）（2）实义动词型：句中的谓语动词为实义动词（也叫行为动词）：a．肯定句中，只出现实义动词，如：I get up in the morning．我早晨起床。
b．否定句中，要在实义动词前面加do（does）＋not，do（does）作助动词，本身无意义，常与not缩写成don't（doesn't），如：I don't like vegetables．我不喜欢蔬菜。
c．一般疑问句，要在句子开头加助动词Do（does），句尾用问号，简略答语用Yes，主语+do （does）．或No，主语+do（does）＋not．如：—Do you like oranges？—你喜欢桔子吗？—Yes，I do．—是的，我喜欢。
（—No，I don't．—不，我不喜欢。
）3,一般现在时的用法1)经常性或习惯性的动作，常与表示频率的时间状语连用。
时间状语：every…,sometimes,often, usually, always,at…,on Sunday I leave home for school at7every morning.2)客观真理，客观存在，科学事实。
The earth moves around the sun.Shanghai lies in the east of China.3)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。
例：Columbus proved that the earth is round..4) if 条件句或when等时间状语从句主将从现第三人称单数的用法在一般现在时中，当主语是第三人称单数时，谓语动词要用第三人称单数形式，即常在动词原形后加-s或-es。
但有些同学们对于哪些主语是第三人称单数还不十分清楚，现归纳总结如下：一、人称代词he, she, it是第三人称单数。
如：He likes watching TV. 他喜欢看电视。
She has lunch at twelve. 她十二点吃午餐。
It looks like a cat. 它看起来像只猫。
二、单个人名、地名或称呼作主语；是第三人称单数。
如：①Han Mei looks like her mother. 韩梅看起来像她的母亲。
②Beijing is in China. 北京在中国。
③Uncle Wang often makes cakes. 王叔叔经常做蛋糕。
三、单数可数名词或"this / that / the+单数可数名词"作主语时，是第三人称单数。
如：①A horse is a useful animal. 马是有用的动物。
②This book is yours. 这本书是你的。
③That car is red. 那辆小汽车是红色的。
④The cat is Lucy's. 这只猫是露茜的。
四、不定代词someone, somebody, nobody, everything, something等及指示代词this, that作主语时，是第三人称单数。
如：①Everyone is here. 大家到齐了。
②There is something wrong with the watch. 这块手表有毛病。
③This is a pen. 这是一支钢笔。
④That is an eraser. 那是一块橡皮擦。
五、不可数名词作主语时为第三人称单数。
如：①The milk is in the glass.牛奶在玻璃杯里。
①The bread is very small.那面包很小。
六、当数字或字母作主语时，看作第三人称单数。
如：①"6"is a lucky number."6"是个吉利数字。
①"I"is a letter."I"是个字母。
六、变化规则V+s; -ch,-sh,-s,-x,-o+es; -辅音字母+y---y变i+es巩固练习题：写出下列动词的第三人称单数形式1. work__________ read__________ clean__________ write__________2. teach__________ wash__________ guess__________ watch__________pass __________ fix __________3. go__________ do___________4. study_______ fly__________ cry__________ play__________ carry __________5. have__________一般现在时疑问、否定句专练一、写出下列动词的第三人称单数形式work________ do_________ fly________ cry________ teach________ carry _______ wash________ read_______ clean_______ pass _______ fix _______write_______ guess______ watch_______ go______ study__________ play__________ have__________二、用括号内动词的适当形式填空。
1.He often________(have)dinner at home.2.Daniel and Tommy_______(be)in Class One.3.We_______(not watch)TV on Monday.4.Nick_______to the zoo on Sunday.5.______they________(like)the World Cup?6.What_______they often_______(do)on Saturdays?7._______your parents_______(read)newspapers every day?8.The girl_______(teach)us English on Sundays.9.She and I ________(take) a walk together every evening.10. There ________(be) some water in the bottle.11. Mike _______(like) cooking.12.They_______(have)the same hobby.13.My aunt_______(look)after her baby carefully.14.You always_______(do)your homework well.15.I_______(be)ill.I’m staying in bed.16.She_______(go)to school from Monday to Friday.17.Liu Tao_______(do)not like PE.18.The child often_______(watch)TV in the evening.19.Su Hai and Su Yang_______(have)eight lessons this term.20.－What day_______(be)it today?－It’s Saturday.21. My father always __________(come) back from work very late.三、按要求改写下列句子.1．This is my pencil.(变一般疑问句)2. These red socks are Kate’s . (变一般疑问句)3. I want to buy a big green bag . (对画线部分提问)4. Mary does not have any books . (变肯定句)5. I often get up at seven o’clock . (用he改写句子)6. He often has rice for dinner. (变为一般疑问句)7. My sister wants to see the comedy. (变为一般疑问句)8. I think this story is boring. (变复数句)9. My mother usually has lunch at 12:12 . (对画线部分提问)10. Li Xing goes home late on Friday evening. (变为一般疑问句)11. There is some orange in the glass. (变否定句)12. She often has a drink after supper. (变为一般疑问句)13. My teachers are in the office. (对画线部分提问)四、改错1.Lily and Lucy doesn't want to clean the blackboard.2.Mr Green likes work in China very much.3.My mother often go to the shop on Sundays.4.She doesn’t likes bread or cakes.5.Where is Jim and Kate now?6.There are some water and leaves in the pool.7.Please give a colour pencil for me.8.They aren’t go to school at the weekend.9.The dog sits between the chair.10.She often works hard and goes to bed in night.。