She argued 'convincingly' [='persuasively'] that more money should be given to public schools.
There is no 'convincing' evidence to support his theory.
Your argument/story isn't very 'convincing'.
(..) vault identical to this one. But it is a fake. It was placed there this past summer. And she never suspected it was a fake. The replica is very convincing. Only a goblin would recognize that this is the true Sword of Gryffindor. Who is the acquaintance? A Hogwarts Professor. As I understand that (..)2011 Harry Potter and the Deathly Hallows: Part 2