make certain
US /meɪk ˈsɜːr.tən/
UK /meɪk ˈsɜːr.tən/

1.
certificar-se, garantir
to ensure something; to take action so that something is certain to happen
:
•
Please make certain that all windows are closed before you leave.
Por favor, certifique-se de que todas as janelas estejam fechadas antes de sair.
•
I need to make certain I have enough money for the trip.
Preciso ter certeza de que tenho dinheiro suficiente para a viagem.