The phrase "make sure" means to ensure or guarantee that something happens or is true. It involves taking necessary steps to confirm that a particular situation or condition is achieved. For example, when you make sure of something, you verify or double-check to avoid mistakes or misunderstandings.
The phrase "make sure" combines the verb "make," which comes from Old English "macian" meaning 'to cause to be, to create,' and the adjective "sure," which comes from Middle English "sure," from Old French "sûr," derived from Latin "securus," meaning 'free from care, safe, or secure.'