To assure someone is to remove someone's doubts. To ensure something is to make sure it happens—to guarantee it. To insure something or someone is to cover it with an insurance policy.

How do you use the word ensure?

ensure something We are working to ensure the safety of people in the city. The book ensured his success. We must take steps now to ensure the survival of these animals. ensure somebody something Victory ensured them a place in the final.

WHEN TO USE ensure and ensures?

As verbs the difference between ensures and ensure

is that ensures is (ensure) while ensure is to make a pledge to (someone); to promise, guarantee (someone of something); to assure.