有時(shí)，主句與從句的動(dòng)作發(fā)生在不同的時(shí)間，主句從句謂語(yǔ)動(dòng)詞的虛擬語(yǔ)氣形式因時(shí)間不同而不同，這種條件句叫做混合條件句。例如：

If you had asked him yesterday， you would know what to do now. 如果你昨天問(wèn)過(guò)他，今天就知道做什么了。

(從句與過(guò)去事實(shí)相反，主句與現(xiàn)在事實(shí)相反。)

If it had rained last night(過(guò)去)， it would be very cold today (現(xiàn)在)。如果昨晚下過(guò)雨，今天就會(huì)很冷了。