Since自从,在某个时间后Itwasthefirsttimetheyhadwonsince1974. 　　某事情由某时间开始,Ihaveknownhersince1983. 　　因为,既然sincetheyhaveobviouslyfoegottentophoneme,Iwillhavetophonethem. 　　before在某某前面,之前,Youwillcallmeanytimebefore10o'clock. 　　Theyshouldbeherebeforelong.=soon 　　Turnthelightsoffbeforeyouleave. 　　when当某某的时候,Hejumpedupwhenthephonerang. 　　指将来的事,when用现在时.IwillcallyouwhenIamready. 　　行将发生的事,既然,考虑到Whydoyouwanttomoremoneywhenyouhavegotenoughalready? 　　Iwillaskherwhenshecomes.