if不能引导主语从句。上句中it是形式主语，其后的从句才是真正的主语从句。要注意...，whether,单词记忆法、语法用法，与whether, 相关例句、名人名言

whether单词相关例句：

The secret of being miserable is to have leisure to bother about whether you are happy or not .——George Bernard Shaw, British dramatist痛苦的秘密在于有闲功夫担心自己是否幸福。英国剧作家肖伯纳。G。
The secret of being miserable is to have leisure to bother about whether you are happy or not . (George Bernard Shaw , British dramatist )——痛苦的秘密在于有闲功夫担心自己是否幸福。 (英国剧作家 肖伯纳 . G .)
A thief is a thief, whether he steals a diamond or a cucumber. 偷多偷少都是贼。
The people may safely be trusted to hear everything true and false, and to form a correct judgment,Were it fall to me to decide whether we should have a government without newspapers of newspapers without a government, I should not hesitate a moment to prefer the latter.——Thomas Jefferson, American president 人民是完全可以信赖的，应该让他们听到一切真实和虚伪的东西，然后作出正确的判断。倘使让我来决定，我们应该是有一个政府而不要报纸呢，还是应该有报纸而不要政府，我会毫不犹豫选择后者。美国总统 杰斐逊.T.
The moon is a moon whether it shines or not. 或名或暗，月亮总是月亮。
The moon is a moon still, whether it shine or not. 月明月暗，终不失其为月亮。
Every form of addiction is bad, no matter whether the narcotic be alcohol or morphine or idealism. ( C. G. Jung )——    任何形式的瘾都是不好的，不管上瘾的是酒精、吗啡还是唯心主义。（荣格）
I sometimes wonder whether the greater rule of all is --- to know how to please.Moliere, J.B. French writer——有时候， 我真的纳闷，莫非一切行为规范中最重要的一条就是学会怎样取悦于人吗法国作家  莫里哀.J.B.

We still don't know whether if it's a boy.
我们还不知道宝宝是不是男孩。

Amy asks whether his friend will be at home.

爱米问他的朋友是否会在家。