1、1Unit 4 Dont eat in class.第 2 课时 Section A(Grammar Focus3c)一、祈使句1含义：祈使句是用来表示请求、命令或建议等的一种句型。其主语一般为第二人称you，但通常省略。祈使句的句末一般用句号，表示较强语气时用感叹号。为了使祈使句显得更委婉、有礼貌，可在开头或结尾加上 please。2祈使句的五种类型Do 型祈使句 实义动词原形其他Listen to me，please.请听我说。Be 型祈使句 be 动词其他Be quiet，please.请安静。Let 型祈使句 Letsb.动词原形其他Lets play football.让我们踢足球吧
2、。Please 型祈使句 Please动词原形其他Please stand up.请起立。Please dont stand up.请不要起立。No 型祈使句 Noving/名词！(表示禁止)No smoking!禁止吸烟！No photos!禁止拍照！3.祈使句的否定形式通常是在谓语动词前加 dont。但要注意以 let 开头的祈使句，其否定形式是 “Dontlet宾语动词原形其他 ”或“Let宾语not动词原形其他” 。4对祈使句的基本回答：(1)A：Tom, take the box to Mr.Wus office.B：肯定回答Yes, I will.否定回答Sorry, I cant
3、 carry it.(2)A：Dont listen to music in class.B：No, I wont.(用于自己之前没做过，同时也表明自己今后也不会做时)或 Sorry, I wont do it in future.(用于自己犯错，被别人禁止时)(3)A：Lets go out for a walk.(“Lets do sth.”常用于提出建议)B：肯定回答Thats a good idea.或 That sounds good.(直接表示赞同)否定回答Oh, no.Its too hot.或 Oh, no.Lets watch TV at home.(可用“No”作否定回答，
4、并适当解释或提出自己的见解)祈使句一般要对方去做的动作是在将来发生。肯定回答时常用“Yes, I will”；否定回答时常用“No, I wont”等。will 为“将要”之意，wont 为 will 和 not 的缩写形式，为“将不；将不会”之意。二、情态动词 can 与 have to1can 能；会2(1)表示做某事的能力，其否定式为 cant。如：Can you speak English?你会讲英语吗？(2) 表示“允许；许可” 。如：You can keep the book for a week.这本书你可以借一周。2have to 必须；不得不其后接动词原形。have to 有
5、第三人称单数形式，即 has to，变疑问句和否定句时要借用助动词 do/does。如：We have to go home after school.我们放学后必须回家。.用括号内所给单词的适当形式填空。1_Dont_play_(not play) with fire(火)2Dont _run_(run) in the classroom.3Let him _not_play_(not play) the computer games.4Can we _eat_(eat) here?5Do you have to _go_(go) to bed before ten at night?.根据
6、汉语意思完成句子，每空一词。1到这儿来。_Come_ _here_2别在走廊里跑。_Dont_ _run_ in the hallways.3快点！_Be_ _quick_！4不要在这儿吃东西。_Dont_ _eat_ here.5让我们骑自行车到那儿吧。_Lets_ _ride_ the bike to get there.按要求完成下列句子，每空一词。1Lily can play the guitar.(改为一般疑问句并作否定回答)_Can_ Lily _play_ the guitar?No , she _cant_2Jack has to play the piano every we
7、ekend.(改为一般疑问句)_Does_ Jack _have_ _to_ play the piano every weekend?3Be quick.(改为否定句)_Dont_ _be_ quick.4You cant eat food in class.(改为祈使句)_Dont_ _eat_ food in class.5You cant be late for class next time.(改为祈使句)_Dont_ _be_ late for class next time.单项选择。(C)1._ listen to music in the classroom.ANot BNo
8、3CDont DDoesnt(A)2.Tom，please _ the classroom now.Aclean Bto cleanCcleans Dcleaning(A)3.Lets _ on time for classes.Abe Bbe notCare Dis(B)4.She has to _ her homework every night.Adoes BdoCdoing Ddid(A)5.Sorry，you _ play basketball in the classroom.Acant BdontCdont have to Ddoesnt.选词填空。阅读短文，从方框中选择适当的词
9、并用其正确形式填空，使短文通顺、意思完整。每词限用一次。fight dirty dish rule beforefollow outside keep one practiceDear Sam，Here are some _1_ for you when your dad and I are not at home._2_， get home early.Dont play _3_ after school.Second，take care of(照顾) your brother and dont _4_ with him.Third, help your grandma do the _5_
10、 after dinner.Fourth，remember to _6_ the piano for one hour every evening.Fifth，go to bed _7_ 10 oclock.The last one, _8_ your room clean and dont leave your _9_ clothes everywhere.Your dad and I will be very happy if you can _10_ the rules.1_rules_ 2._First_ 3._outside_4_fight_ 5._dishes_ 6._practice_7_before_ 8._keep_ 9._dirty_10_follow_
