表示现在及将来情况(表示纯然假设或实现的可能性不大的情况):
ifiwereyou,iwouldn’tloseheart.
howniceitwouldbeifyoucouldstayabitlonger.
表示过去情况的虚拟条件句(与事实完全相反的假设情况),谓语主要形式如下:
shewouldhavecomeifwehadinvitedher.
ifihadn’ttakenyouradvice,iwouldhavemadeabadmistake,
youwouldn’thavecaughtcoldifyouhadputonmoreclothes.
有时候,条件从句表示的动作和主句表示的动作,发生的时间是不一致的(如一个是过去发生的,一个是现在发生的).这时,动词的形式要根据表示的时间来调整.这种句子可以称为错综时间条件句.
ifhehadreceivedsixmorevotes,hewouldbeourchairmannow.
ifwehadn’tgoteverythingreadybynow,weshouldbehavingaterribletimetomorrow.
有时假设的情况并不以条件从句表示,而是通过一个介词短语来表示.
withoutmusic,theworldwouldbeadullplace.
wecouldhavedonebetterundermorefavorableconditions.
thatwouldhavebeenconsideredmiraculousinthepast.
butforthestorm,weshouldhavearrivedearlier.
如果条件句从句中包含有were,had,should或could,有时可把if省略掉,并把were,had,should或could放在主语前面.
hadwemadeadequatepreparation,wemighthavesucceeded.
shouldtherebeaflood,whatshouldwedo?
wereitnotfortheirassistance,wewouldbeinseriousdifficulty.
