if条件状语从句和宾语从句.pptx

AdverbialClauseofCondition

if引导的条件状语从句宾语从句;Sheisdoingherhomework.;Ifyouplaycomputergamesonweekdays,;1)条件状语从句通常由if或unless(=ifnot)引导，从句中常用一般时代替将来时，即if或unless后的句子谓语用一般现在时。但是，主句则通常用将来时，情态动词或祈使句。

;

1.如果主句是一般将来时，从句则用一般现在时。

Ifitrains（从句），Iwillstayathome.

I’llgowithyouifyoudon’twanttogoalone（从句）.

2.如果主句含有must,may,can等情态动词，从句也要用

一般现在时。

Ifyoudrivetoofast,youmayhaveanaccident.

Youmuststopifthetrafficlightisred.

3.如果主句是祈使句，从句同样要用一般现在时。

Don’tgoandplayfootballifyoudon’tfinishyour

homework.

PleasecallmeifhecomesnextSunday.

;If引导条状语从句时，从句中用一般现在时代替一般将来时。;Ifyouarefreethisweekend,

whatwillyoudo?;Ifyouwanttogetgoodmarks,

dowhat?Don’tdowhat?;If条件句的替代形式：

（1）祈使句+and/or+陈述句（谓语动词通常用将来时态）。其中，and表示句意顺承；or表示转折，意为“否则”。

e.g.Ifyouworkhard,you’llpasstheexameasily.

=Workhard,andyou’llpasstheexameasily.

Ifyoudon’tworkhard,you’llfallbehindothers.

=Workhard,oryou’llfallbehindothers.

;（2）用介词with,without的替代形式：

e.g.Ifthereisnowater,thefishmaydie.

=Fishmaydiewithoutwater.

Ifyouhelpme,I’llfinishmytaskontime.

=Withyourhelp,I’llfinishmytaskontime.

;If在宾语从句中翻译为“是否”

If在条件状语从句中翻译为“如果”;2.if在从句中的位置不同;3.时态要求上有区别;1.Canyoutellmeifshecancometothemeeting?

2.Shewillnotgothereifitisrainytomorrow.

3.Ican’tguessifshewillbeangry.

4.Ifwehelpeachother,wewillgetgoodresults.;1IfI_______________(notunderstand）,Iwillaskmyteacherforhelp.

IfI__________(copy)yourhomework,Iwillcheatmyself.

Idon’tknowifit______(rain)tomorrow.

MyteacheraskedmeifI_________(finish)myhomeworkalready.;if的用法