When to Use Insure, Ensure, and Assure

These are probably three of the most misused words in the English language, but it doesn’t have to be this hard! Below is a simple method to remember when/how to use the right word, so that your credibility as a writer or subject matter expert does not needlessly suffer.

  1. Insure

First and foremost, it’s almost never correct to use “insure” in your writing, unless you’re talking about GEICO, State Farm, or whole life insurance. We all know what insurance is; don’t use insure unless you’re talking about insurance.

With that one out of the way, you will be much more likely to use the correct word.

  1. Ensure vs. Assure

Think of it this way – we assure personally and ensure systematically. Look at some simple examples:

A truck driver might assure his employer that he will not speed. “I promise I won’t go any faster than 65 mph.” That is a personal assurance. But the trucking company can ensure that he does not speed by installing throttle limits that won’t let the truck exceed 65 mph, or they can monitor the speed in real time with GPS. These are systematic ways of ensuring that the truck does not speed.

A teenager can assure her parents that she will not drink alcohol at the weekend party, but her parents can ensure that she doesn’t drink at the party by not letting her attend it.

A politician assures his constituents that he is fiscally responsible, but a law requiring a balanced budget ensures it.

A simple mnemonic to remember this is APES – Assure Personally, Ensure Systematically. It’s so easy, even an ape can do it!


Duane Carey runs IMPACT Marketing & Public Relations, a full-service marketing company in Columbia, Maryland that – among many other services – ghost writes content for dozens of clients. He can be reached at 410-312-0081 or dcarey@impactmarketing.net.

About the author