大家好，日前和朋友討論到一句用法，請各位不吝賜教：
I don’t know the reason for him doing this.
（我不知道他這麼做的原因）
這句文法是正確的嗎？如果改成
I don’t know the reason of him doing this.
呢？因為我想說”the reason of him”感覺可以當作類似所有格：his reason 的效果？
還是英文沒有這種用法><？
我們已知這句如果要用
I don’t know his reason for doing this.
或是
I don’t know why he did this.
是可以的，那麼第一、二句呢？
感謝各位！

是不是不用接介系詞？然後應該在前面加疑問--＞ I don't know what the reason he did this也可能he前面可以加makes查了一下，reason 後面是接for，要用of的話必須用byreason of接why的話可以省略why

I don't know the reason why he did this.經詢問過母語人士後得到的回答是：All of those sensors can be correct. They all said the same thing. Themost common way would be... I don’t know the reason he did this.更正*sentences* 對方打錯字。