1/4祈使句(一)概念:用来表示请求、命令、叮嘱、邀请、劝告的句子是祈使句。(二)一般祈使句(省略第二人称主语you)1.肯定句:动词原形+……Bebrave.Standup.Stoptalking!Comeonandjoinus!a.有时,为了加强语气,可以在动词之前加do.Dostudyhard.Dositdown.b.为了使语气显得客气,可在祈使句的句首或句尾加上please.Please在句尾时,之前一定要加一个逗号。Pleasecomehere.Gothisway,please.c.祈使句有唤语,一定要用逗号隔开,放在句首或句尾。LiMing,comehere.Hereyouare,Eric.2.否定句:Don’t+动词原形+……Don’tswimintheriver.2/4Don’tbelate.Pleasedon’tbenoisy.Don’ttellher,please.(三)Let祈使句(含有第一、三人称主语)1.肯定句:Letsb.dosth.Let’sgoswimmingonSunday.Letmetryagain.LetTomgotherehimself.Letthenewsbeknown.Leteachmandecideforhimself.2.否定句:Letsb.notdosth.或Don’tletsb.dosth.Don’tletherwastetime.Don’tlethimhearyousaythat.Lethernotdoitalone.Let’snotsayanythingaboutit.Don’tletthemplaywithfire.3.注意:Let’s表示包括对方。Letus表示不包括对方。Let’sgo,shallwe?(包括对方)Letusgo,willyou?(请求对方许,不包括对方)3/4(四)句型转换:祈使句+and/or+陈述句祈使句相当于if引导的条件状语从句。Useyourhead,andyouwillfindaway.=Ifyouuseyourhead,youwillfindaway.Workhard,oryouwillfail.=Ifyoudon’tworkhard,youwillfail.练习:Comeearly,andyouwillcatchthefirstbus.=Comeearly,oryouwillmissthefirstbus.=连词:1、and,then,andthen就,那么2、or,orelse,otherwise否则,要不然比较:1、Comeearlyandyouwillcatchthefirstbus.早点来,你就能赶上第一班车。2、Comeearly,oryouwillmissthefirstbus.早点来,不然赶不上第一班车了。3、Useyourhead,thenyouwillfindaway.开动脑筋,那么你就能找到办法。4、Useyourhead,oresle,youwon'tfindaway.开动脑筋,否4/4则你就找不到办法。5、Workhard,andthenyouwon'tfail.努力干,你才不会失败。6、Workhard,otherwiseyouwillfail.努力干,不然你会失败的。