1.I would not have arrived late,if my watch had not been slow.
2.If he had studied harder last term,he would have passed the exam.
3.We would not have finished the work on time without your help.
其中一二句屬于if引導(dǎo)的和過(guò)去事實(shí)相反的虛擬語(yǔ)氣,所以if從句用過(guò)去完成時(shí),主句用would have done第三句屬于委婉虛擬語(yǔ)氣,需要憑借意思判斷的,
這種較含蓄的虛擬還可以用other wise ,but for等等