© Judi Birnberg Collage with handmade paper
I assure you that you will understand the differences among these three similar words. See? You already knew what ASSURE meant in that sentence: to give a guarantee or to make certain.
ENSURE also means to make certain; you might say, “I can ensure you the package you ordered will be delivered today.” Note the use of can with ensure.
INSURE has to do with money (think about insurance). “You need to insure that package at the post office.”