These two are used interchangeably at times, and we might be at the point where the distinction is losing all meaning in our everyday speech. (But for now, let’s at least try to keep the difference alive!)

To be more precise, we use insure when we mean ensure; it’s rarely the other way around.

The distinction is easy. To insure something is to put some insurance on it. We insure our houses, our cars, and other things of value. We even have life insurance, which is more like death insurance, but that’s another issue….

To ensure something is to make sure that it happens, to safeguard or guarantee an action.

• We ensure someone that Grandma will behave this time by sitting next to her throughout the evening.
• The company delivering our package tries to ensure that it will arrive on time.
• Teenagers wanting to keep their privilege will ensure they are home by curfew.

Since the most common error is to say insure when we mean ensure, if we just keep using insure when we are referring to insurance, it will likely ensure a proper usage of these words.