1、Unit 4 Then and now语法梳理：一般过去时VS一般现在时精讲精练(含答案)v 比较：一般过去时VS一般现在时Twenty years ago, Mrs Brown made friends at school. 二十年前，布朗夫人在学校交朋友。 Now she has e-friends from all over the word. 现在她的网友遍布全世界。 一般现在时1. 定义：指经常性或习惯性的动作或存在的状态 若指经常性、习惯性的动作，谓语动词用行为动词； 若指经常性、习惯性的状态，谓语动词用be动词。 动词原形/三单2. 谓语动词 am/is/are3. 标志词：ev
2、ery day, always, usually, often, sometimes, seldom(很少), never(从不)4. 动词三单变化规则：(1) 一般在动词尾加s，如：look-looks, read-reads;(2) 以s, x, sh, ch以及o结尾的动词加es，如：catch-catches, go-goes, do-does;(3) 以“辅音字母+y”结尾的动词，变y为i，再加es, 如：fly-flies;(4) 特例：have-has注：当主语是he, she, it以及单数，不可数名词时用三单。5. 句型转化肯定句：I am at home.I like ca
3、ts.He likes lions.否定句：I am at home.I dont like cats.He doesnt like lions.一般疑问句：-Are you at home?-Do you like cats?-Does he like lions?-Yes, I am./No, Im not.-Yes, I do./No, I dont.-Yes, he does./No, he doesnt.特殊疑问句：Where are you?What do you like?He likes lions. 一般过去时1. 定义：指发生在过去的动作或过去存在的状态。 指发生在过去的动
4、作或事情，谓语动词用行为动词的过去式； 指过去存在的状态，谓语动词用be动词的过去式was, were。 规则的动词加ed，不规则的特殊记2. 谓语动词 was/were3. 标志词：yesterday, yesterday morning/afternoon/evening last week/month/year/term上一周/日/去年/上个学期 this morning/afternoon/evening just now(刚才)；a week ago(一周前); long long ago(很久以前) one day(一天); the day before yesterday(前天)
5、4. 动词过去时式的变化规则(1) 一般直接在词尾加-ed。(2) 以不发音的e结尾的动词在词尾加-d。(3) 以辅音字母加y结尾的动词,变y为i,再加-ed。(4) 以一个元音字母加一个辅音字母结尾的重读闭音节动词,先双写这个辅音字母,再加-ed。(5) 不规则动词过去式的变化,需要同学们逐个记忆。例：watchwatched likeliked studystudied stopstopped arewere go-went have-had read-read5. 一般过去时的三种句型结构：句型结构例句肯定句主语+行为动词的过去式（+其他）I did homework yesterday
6、.主语+was/were+其他I was very happy yesterday.否定句主语+didnt+行为动词原形（+其他）I didnt do homework yesterday.主语+was/were+not+其他I wasnt happy yesterday.一般疑问句Did+主语+行为动词原形（+其他）？Did you do homework yesterday？肯定回答：Yes，主语+did.否定回答：No+主语+didnt.Yes, I did. 是的，我写了。No, I didnt. 不，我没写。Was/Were+主语+其他？Were you happy yesterda
7、y？肯定回答：Yes, 主语+was/were.否定回答：No，主语+was/were+not.Yes, I was.是的，我很开心。No, I was not.不，我不开心。【考题精练】一、 按要求写词。1.can（过去式） 2.went（原形） 3.take（过去式） 4.fly（过去式） 5.read（过去式） 6.saw（原形） 7.couldnt（完整形式） 8.shop（现在分词） 9.e-mail（复数） 10.buy（过去式） 二、 用所给词的适当形式填空。1.My grandmother is (read) e-books on the Internet now.2.My p
8、arents (use) the telephone (call) people before.3.Liu Tao (write) a letter to his e-friend yesterday morning.4.Twenty years ago,she usually (make) friends at school.5.Mike (watch) TV after dinner last night?6.Mrs Black (buy) a lot of things in the supermarket yesterday morning.7.I (go) to Bens birth
9、day party last night and (take) him a gift.8.Helen (eat) a hamburger and drinks a bottle of milk every morning.9.Liu Tao (get) a new computer from his father last weekend.10.Eight years ago,Ben (cannot) write,but now he can write many words.三、 按要求完成句子。1.He used the telephone to call people twenty ye
10、ars ago.(改为同义句)He people the telephone twenty years ago.2.There were some newspapers on the table just now.(改为一般疑问句) newspapers on the table just now?3.They found a small lake in the forest.(改为否定句)They a small lake in the forest.4.Nancy could draw pictures five years ago.(对画线部分提问) Nancy five years a
11、go?5.Miss Li is telling us a story now.(用yesterday替换now改写句子)Miss Li a story yesterday.v could表达某人过去会做某事Six years ago, Mike could read and draw, but he could not write.六年前，迈克会读书和画画，但是他不会写字。解析：could是can的过去式，意为“能够，会，可以”，表示某人具有做某事的能力；其否定形式为couldnt =could not; 两者没有人称和数的变化，其后都要接动词原形。即 can/could + 动词原形 肯定句
12、型结构：主语 + could + 动词原形（+其他）. 否定句型结构：主语 + couldnt + 动词原形（+其他）. 一般疑问句结构：Could + 主语 + 动词原形（+其他）？ 肯定回答：Yes, 主语+could./否定回答：No, 主语+couldnt. 拓展：could也可以表示委婉、客气地提出问题或陈述看法，此时可以与can互换使用，但could的语气较can委婉，两者没有时态上的区别。典例： When I was five years old, I could sing, but I couldnt dance. 当我五岁的时候，我会唱歌，但是我不会跳舞。【考题精练】一、 单
13、项选择。( )1.Mr Green because Tom didnt him in class.A.gets angry;listened to B.gots angry;listen C.got angry;listen to( )2.Ten years ago,I eight years old and you ten.A.was;were B.was;was C.were;are( )3.The boy skate,but the girl .A.could;didnt B.could;couldnt C.couldnt;did( )4.Sam can make a sentence
14、“ago”,but Bobby .A.for;doesnt B.with;can C.with;cant( )5.Helen couldnt dance sing five years ago.A.or B.and C.to二、 根据中文提示完成句子。1.老约翰以前听收音机获取新闻。Old John the radio before.2.苏海的爷爷喜欢看报纸。Su Hais grandpa likes .3.现在，我们可以随处给我们的朋友们打电话。Now we can .4.五年前，我不会溜冰，但是我会游泳。I skate ,but I .5.在周末，我们通常步行去超市购物，然后去看电影。At
15、 weekends,we usually the supermarket to do ,and then we go to the cinema.参考答案一、 1.could 2.go 3.took 4.flew 5.read 6.see 7.could not 8.shopping 9.e-mails 10.bought二、 1.reading 2.used,to call 3.wrote 4.made 5.Did,watch 6.bought 7.went, took 8.eats 9.got 10.couldnt三、 l.called,with2.Were there any3.didnt find 4.What could,do 5.told us四、1.C 2.A 3.B4.C解析：make a sentence with,意为“用造句”；but表示转折，前半句表示肯定，则后半句表示否定。故选C。5.A五、1.listened to,for news 2.reading newspapers3.call our friends anywhere 4.couldnt,five years ago,could swim 5.walk to,shopping
