英语语法 Nobody but him knows it中为什么but后要用him而不用he

这句话中，nobody是主语，but是介词，him作but的宾语，故用宾格。这句话的主干其实是nobody knows it.这种用法在英语里叫做“就远原则”，如：The teacher as well as his pupils likes playing PC games. 注意，本句中的谓语用的是第三人称单数形式，因为主语是teacher,而不是pupils。希望以上解答能够对你有帮助

习惯的用法而已
would you mind me opening the window.
也可以说是
would you mind me opening the window.
一切皆是习惯而已。

but = except 除... 之外,是介词，后面的名词做介词的宾语，所以用宾格的him, 而不用主格的 he.本句的主语是nobody.