1. to choose or pick something deliberately and intentionally, with a specific goal or reason in mind
The teacher selected on purpose the students who needed extra help.
A professora selecionou propositalmente os alunos que precisavam de ajuda extra.
2. to make a deliberate choice from a range of options
He selected on purpose the red wine to pair with dinner.
Ele escolheu propositalmente o vinho tinto para acompanhar o jantar.