ADJ in n
The 'adamant' groupThese adjectives indicate that someone believes something strongly, or is determined to do something, or talks about something in a way that indicates strong belief or determination.
The noun group following the preposition in usually begins with a possessive determiner.
She is adamant in her refusal to make any statement.
Both men are military officers firm in their belief that the nation's interests and their own are one and the same.
Last week the fans were loud in their support for their manager, his players and his tactics.
It is perhaps no surprise that the legal profession has been vocal in its opposition to the new body.
The preposition in is sometimes followed by an '-ing' clause.
adamant firm forthright frank loud resolute steadfast unequivocal vehement vocal vociferous
He's very firm in saying that he has to be allowed to return to Haiti.
I think they've established their goals. I think they're resolute in pursuing them.