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.