make sure

verb4

1. •
   To ensure that something specific happens, is done etc., or of something happening.

   • I'm going to make sure that I get to the interview on time.
   • I expected to be able to get to the interview on time, but I left home earlier than usual just to make sure.
2. •
   To make oneself certain (of something, or that something is the case); to verify, to ascertain.

   • When you leave, make sure you have locked the door behind you.
   • Make sure of your sources before you publish.
3. •
   (no longer used) To feel certain of something; to be convinced.

   • ‘I put my name to a bill for Fred; it was for a hundred and sixty pounds. He made sure he could meet it himself.’ — 1872
4. •
   (no longer used) To betroth.

   • […] then his marriage shall be solemniz'd, / For wrote you not that I haue made him sure / Vnto our Cosin, the Earle of Glosters heire. — 1594