我怀疑他是秘密的法西斯分子。

I suspect he's a closet fascist.

《牛津词典》

我怀疑他被解职是人事上的原因。

I suspect that he was dismissed for political reasons.

《牛津词典》

我原则上是同意它的，但我怀疑在实践中它是否会发生。

I agree with it in principle but I doubt if it will happen in practice.

《柯林斯英汉双解大词典》

All right, this is actually a very old piece of imperative knowledge for computing square roots, it's attributed to Heron of Alexandria, although I believe that the Babylonians are suspected of knowing it beforehand.

好，这是一个很古老的,关于计算平方根的程序性知识，是亚历山大的海伦提出的，不过我怀疑在那之前,巴比伦人就已经猜想过了。

麻省理工公开课 - 计算机科学及编程导论课程节选

Literary theory, as I say, is skeptical about the foundations of its subject matter and also, in many cases, about the foundations of what it itself is doing.

就像我说的，文学理论，是对创作题材的怀疑,在很多情况下，也是对自身所做之事的基础的怀疑。

耶鲁公开课 - 文学理论导论课程节选

Most of the influence,I suspect, was going one way in those days- from the more advanced civilization of the east to the Greeks.

而且我怀疑,绝大多数影响,在那些日子中是单边流向的,从东方更高级的文明流向希腊

耶鲁公开课 - 古希腊历史简介课程节选