Garoto humilhado tenta provar que seus vídeos prestam

What does “não presta” mean in Portuguese?

Textbooks teach prestar in fixed pairs: prestar atenção (“pay attention”), prestar serviço. Everyday speech gives it a blunter job — being any good. Isso não presta is “that’s no good”; será que vai prestar? is “is this going to be any good?”. Said of a person, ele não presta is a moral verdict rather than a review: he is worthless, bad news.

The positive is rarer but alive: presta para alguma coisa?, “is it good for anything?”, and the flat não presta para nada. The related adjective prestativo went the opposite way and means helpful, obliging. The whole clip hangs on this sense — everyone told the boy os vídeos dele eram ruins, and the question he sets out to settle is será que isso vai prestar?