He boasts that he is an authority.

他夸口说自己是权威。

《新英汉大辞典》

He boasts of owning a digital camera.

他吹嘘自己有了数码照相机。

youdao

He boasts of [about] having a fine voice.

他夸耀自己有一副好嗓子。

youdao

And in the inscription he writes, he boasts: "And the god Chemosh said to me, go, take Nebo from Israel.

他在题词中写到，他吹嘘到：,基摩神对我说，去，从以色列手中夺回尼波山。

耶鲁公开课 - 旧约导论课程节选

You don't want to be someone like the fisherman who boasts about one big fish that he caught because it's not-- we're talking about livelihoods.

不要像那个渔夫一样,因为曾经捕过一条大鱼而到处炫耀-,我们说的是维持生计的问题。

耶鲁公开课 - 金融市场课程节选

"I think it's going to be a Harvard Business School case study someday, " he boasts.

FORBES: The Beer Baron

Controversy has dogged Kieren Fallon's career, yet he boasts few equals in the saddle.

BBC: Kieren Fallon

He boasts of his success rate - but can't say specifically how many people he has cured.

BBC: Mentally ill patients in Indonesia held in chains