我从不怀疑自己的能力，只怀疑自己有没有努力。

I never doubt my ability, only doubt I have no effort.

youdao

史妮救女士：我不会对施奈克失望的，我从不怀疑这家伙的品德。 这甚至足以让他忠诚于他自己的恶行。 （玛丽娅上）我亲爱的玛丽娅，你好啊?有什么事吗？

Lady Sneerwell:I'm not disappointed in Snake, I never suspected the fellow to have virtue enough to be faithful even to his own villainy. (Enter Maria) Maria my dear, how do you do, what's the matter?

youdao

我的狗从不怀疑他有权拥有自己的空间。他知道自己的领地的范围，并且保护它不受侵犯。

My dog has no questions about his right to his space. He knows his territory, and he protects it.

youdao