I have the ability to do that=iam able to do that =i am capable of doing that =i have the capability in/of doing that这些都是 单词的 固定用法 所以 不能写成I have the ability of doing that.
这句话想表达的意思是我有能力去做那件事,若改用of的话,就有了为了那件事而有能力的误解,这不算语法问题,to do的形式表达了去做的意愿,of偏向目的I went to the park to pick up flowers for my girlfriend.这里的to pick up就是目的啊,to不就表示目的吗??如果你只记语法,估计是不行的,语言那么灵活,很多用法要感受,所以你会分不清of...