條件狀語從句

If引導(dǎo)條件狀語從句位置：從句可放在主句之前或之后，但是放在主句之前須有逗號隔開eg:如果我有足夠的錢，我就去環(huán)游世界If引導(dǎo)條件狀語從句

定義：if

“如果,假如”它引導(dǎo)的句子表示某事發(fā)生所需的條件，即“在…條件下，某事才能發(fā)生”，在句子中充當(dāng)狀語，因此稱之為條件狀語從句。（If引導(dǎo)的條件狀語從句表示假如有從句的動作發(fā)生，就會有主句動作的發(fā)生）IfIhaveenoughmoney,Iwilltravelaroundtheworld=IwilltravelaroundtheworldifIhaveenoughmoneyif（如果）引導(dǎo)的條件狀語從句主祈從現(xiàn)主將從現(xiàn)從主有逗主從無逗if引導(dǎo)的條件狀語從句時態(tài)主將從現(xiàn)祈使句情態(tài)動詞Iwill

singasong

ifIamhappy.主句從句Don’tcrosstheroad

if

thelight

is

redYou

must

stop

if

thetrafficlightisred.用法：1.如果主句是祈使句，從句要用一般現(xiàn)在時。

Don’tgoandplayfootballifyoudon’tfinishyourhomework.

PleasecallmeifhecomesnextSunday.if（如果）引導(dǎo)的條件狀語從句:2.如果主句是一般將來時，if從句則用一般現(xiàn)在時。

Ifitrains（從句），Iwillstayathome.I’llgowithyouifyoudon’twanttogoalone（從句）.

3.如果主句含有must,may,can等情態(tài)動詞，if從句也要用一般現(xiàn)在時。

Ifyoudrivetoofast,youmayhaveanaccident.Youmuststopifthetrafficisred.1.Ifyou____(want)tolistentomusic,_____(choose)aCD.2.Ifyou___(buy)anewcamera,____(get)agoodone.3.Ifthelight___________(notcome)on,____(wait)foroneminute.4.Ifit___________(notwork),_____(wait)aminuteandthen_____(try)again.5.Ifyou________

(notknow)howtousethecamera,____(read)theinstructions.wantchoosebuygetdoesn’tcomewaitdoesn’tworkwaittrydon’tknowreadCompletethesentences.

1.I’msureifhe_____(go)totheparty,he________(have)agreattime.2.Iftherain_______(stop)tonight,wewillgotothecinema.3.I’llbuyacomputerifI______(have)enoughmoney.4.You_________(notget)nervousifyou_____(do)enoughexercise.5.Iwanttoknowifhe_________(come)tomorrow,ifhe_______(come),I__________(give)themassagetohim.goes

willhave

stopshave

won’tgetdo

comes

willcome

willgive1.Ifitstopssnowingwe___goout.2.Ifyouwanttoloseweightyou__________eatlessbread3.We____walkthereifwecan'tfindabus.4.Ifyouloseyoucellphone,you____feelupset.5.Ifyoulietoyourbestfriend,you__________feelsorry.canmust/shouldcanmaymust/mightif從句還表示不可實現(xiàn)的條件或根本不可能存在的條件，也就是一種虛擬的條件或假設(shè)。從句多用一般過去時或過去完成時，表示對現(xiàn)在或過去的一種假設(shè)。如：IfIwereyou，Iwouldinvitehimtotheparty．如果我是你，我會邀請他參加聚會。Iwouldhavearrivedmuchear