one do sth by/on oneself 是比较常见的句型你要是非要用One oneself does sth,也可以例句: It's me myself did it!(这事是我一个人干的!)另外 ,口语中我们也经常见到one do sth oneself例如:He broke his arm himself(胳膊是他自己摔断的)
我就以“我会亲自去做这件事的”为例吧。I will do it by myself 口语可以缩略为I'll do it myself还有一种不用oneself的说法I will do it on my own 另外One oneself does sth.是可以的。举两个例子“你应该亲自参加这个实验,而且还要以实验一部分的身份参加。”You yourself should take part in this experiment as a component.“他手下的杀手都失败了,所以他只好亲自动手暗杀了那个特工。”He himself assassinated that agent because all his stupid killers failed.