I'm doubtful of what he said.

怀疑他所说的话。

youdao

He was doubtful of the patient's recovery.

他怀疑病人是否痊愈。

youdao

Most netizens were doubtful of the necessity of this costly public washroom.

大多数网民质疑有没有必要设立这么昂贵的公厕。

youdao

"Well they certainly will be doubtful of it unless President Obama makes a strong argument.

VOA: standard.2009.09.22

But some are doubtful the reforms will work. Boston University School of Law professor Cornelius Hurley.

VOA: standard.2010.03.16

Even as Haitians have been outraged by Minustah's wrongdoing, they have become increasingly doubtful of the benefits it provides.

ECONOMIST: The UN in Haiti

U.S. officials are doubtful of any major breakthrough in Kazakhstan, in part because of Mr. Khamenei's fixation on the June elections.

WSJ: Iran Cools Nuclear Work as Vote Looms

The driver, doubtful of the whole affair, stood by while the father and son lifted Nawab and the motorcycle thief into the back.

NEWYORKER: Nawabdin Electrician