whether的用法when的用法如何区分这两个用法

whether的用法：1.(引导名词从句)是否Ask him whether he can come or not.问问他是否能来.I don't know whether you like flowers,sir.先生,我不知道您是否喜欢花. 2.(与or连用,引导状语从句)不管是...(或是)We'll go on with the work,whether we can find the necessary tools or not.不管我们能否找到所需的工具,我们要把这件工作做下去.在引导定语从句时,一般情况下whether和if都可使用,但whether的适用范围要比if广,实在不知道应用什么的时候,选whether.例如从句若出现了选择项：A or B,只能用whether而不能用if但要注意,从句为否定句时,只能用if,而不能用whether when副词adv.什么时候（用于时间的表达方式之后）在那时,其时 3.其时；当时；当场连接词conj.引导时间状语时,翻译为：当……时候,如：Don’t be afraid of asking for help when it is needed.类似并列连词,翻译为：在那时,常用于be about to do...when,hardly...when等句型中.如：We were swimming in the lake when suddenly the storm started.表原因,翻译为：既然,.如：Why do you want a new job when you’ve got such a good one already?连接副词,用于名词性从句中.如：I remember when this used to be a quiet village.（此句为宾语从句）关系副词,用于定语从句中.如：The film brought the hours back to me when I was taken good care of in that far-away village.表让步,翻译为：即使,.如：The enemy held out when they must have known there was no hope.代词pron.什么时候那时

when是时间状语