The phrase "about his credibility" is correct and usable in written English.
It can be used when discussing someone's trustworthiness or reliability in a particular context.
Example: "The committee raised concerns about his credibility as a witness during the trial."
Alternatives: "regarding his trustworthiness" or "concerning his reliability."
Ask about his credibility, and he purses his lips.
Back at Penn State, Mr. Ansorge worried about his credibility with his audience.
But questions about his credibility have led the Brooklyn district attorney's office to reopen all of his trial convictions.
Chafee told reporters Wednesday he is "much less likely" to support Bolton because of questions about his credibility.
Despite weeks of criticism and questions about his credibility, Mr. Gonzales gave no sign that he planned to step down.
But this ambition crumbled amid questions about his credibility and a failed tilt at the Stoke Central by-election.
"I'm very confident in the relationship that we have in this room, and the trust that has been established between us," he said at his daily briefing on Monday, in response to questions from David Gregory of NBC News about whether his credibility with reporters and the public was in doubt.
As it is, Flint, when HSBC reports full-year results next Monday, will have to deal with questions about his own credibility.
The Bush campaign, which called Mr. Gore's visit a gimmick, said the vice president was raising more questions about his own credibility than he was about the stewardship of Texas, accusing him of distorting the budget situation.
Last year, the chairman of the panel, Devin Nunes of California, stepped away from leading the Russia investigation over questions about his own credibility to run it in a fair and bipartisan manner.
But the western diplomat cautioned: "I would not assume he will stay indefinitely," and adding that Brahimi might have "concerns about his own credibility" if he allows the process to continue to play out like a broken record.
