I'm not good at spoken English这句话为什么不是at speaking

I'm not good at spoken English这句话为什么不是at speaking I'm not good at speaking in English since it hasn't passed m i'm no good at this 为什么不是not good My brother is not good at speaking English?I suggest___Engli I am not good at spoken English.请说明一下句子成分. I'm not good ____是to speak 还是at speaking还是at speak I'm not very good at _math,but I'm good at English i m not good at He‘s very good at spoken English I am not good at English lucy with kitty is not good at English,为什么用is not,不是are not i'm not good at english中的at可不可以替换成in