t'assurer que

to make sure that

→ te
phrase Uncommon #23,660
to make sure that In this reflexive construction, it means to check or ensure that something is true or happens.
FR: Tu dois t'assurer que tout est prêt.
EN: You have to make sure everything is ready.

Tu es venu t'assurer que j'étais bien mort !

You came to make sure I was really dead!

— Shower (1999)

Je peux t'assurer que tu as tort.

I can assure you that you're wrong.

Tu ferais bien de t'assurer que c'est vrai.

You’d better make sure it’s true.

Tu dois t'assurer que je continue à boire cette potion.

You have to make sure I keep drinking this potion.

— Harry Potter et le Prince de sang-mêlé (2009)

Je te prie de t'assurer que ta ceinture est attachée.

Please make sure your seat belt is fastened.