missohmygod
whether or not例如:It ceased to matter whether or not he sold his work. 他是否卖掉了他的作品已无关紧要。if例如：I wonder if she is ill.不知她是否病了。whether例如：His nationality isn't relevant to whether he's a good teacher. 他的国籍与他是否是位好老师无关。I'm uncertain whether to go or not.我不能肯定去还是不去。
大哈哈a呦呦
he want to know whether Tom has arrived there.想知道，want to表示，是否whether从句，已经到那，所以用has arrived there。
妞妞们要健康
可以用whether或者if.但是if只用在及物动词后的宾语从句中.如：I don't know if/whether you are right.不可以用在名词性从句中（主语从句,表语从句,同位语从句）,以及介词后面. whether用法比较广泛.后面可以加or not,或者 to do sth.如 Whether or not he is right is unknown. whether he is right or not is unknown. I want to know whether to go out or not.
