1.的确,inwhich可以等于when,也可以等于where,但不会等于why. 　　关键是看定语从句中缺少时间状语还是地点状语. 　　2.例如： 　　1）I'llneverforgetthesedaysin/duringwhichIstayedwithyou. 　　=I'llneverforgetthesedayswhenIstayedwithyou. 　　我永远不会忘记我和你待在一起的日子. 　　其中：in/duringwhichIstayedwithyou=whenIstayedwithyou 　　=Istayedwithyouin/duringwhich=Istayedwithyouin/duringthesedays 　　2）ThisisthecityinwhichIstayedlastyear. 　　=ThisisthecitywhereIstayedlastyear. 　　这就是那个去年我待的地方. 　　其中：whereIstayedlastyear=inwhichIstayedlastyear 　　=Istayedinwhichlastyear=Istayedinthecitylastyear. 　　3.另外,有的inwhich找不到合适的关系副词代替. 　　如：Idislikethewayinwhichyoutreatme. 　　我不喜欢你对待我的方式. 　　其中：inwhichyoutreatme=youtreatmeinwhich 　　=youtreatmeintheway 　　4.forwhich=why 　　如：Canyoutellmethereasonwhyyouwerelate? 　　=Canyoutellmethereasonforwhichyouwerelate? 　　你能告诉我你迟到的原因吗? 　　其中：whyyouwerelate=forwhichyouwerelate 　　=youwerelateforwhich=youwerelateforthereason