Ensure or Insure? How to Tell the Difference


Don’t you hate it when two words differ by just one letter? Choosing between words like ensure or insure can present a challenge.

Running a spellcheck on a document won’t always give you the correct answer! I received a reminder of that when spellcheck disagreed with me on selecting between ensure and insure.

I wrote an email to a landlord about an insurance quote I received. In the email, I wrote that the company would be able to insure the property with no problem.

You probably picked up on the word insurance. If you suspected that should serve as a clue, you suspected correctly!

Spellcheck, unfortunately, did not share our opinion of the word. It placed a little red line below insure. When I hovered over that marked word, a popup suggested ensure.

Well, spellcheck is supposed to know everything, so for a moment, I changed the I to an E. But almost immediately, I knew that wasn’t correct. I went right back to the word insurance. Insurance agents insure things.

So I changed ensure back to insure, red line be damned.

But I did have to consult the dictionary just to make sure that what my gut told me was, indeed, correct.

Let’s consider the two words.

The Online Etymology Dictionary tells us that ensure entered English in the late 14th century. It comes from the Anglo-French enseurer, from en- “make” and the Old French seur “sure.” That tells us that ensure means “to make sure.”

In fact, Merriam-Webster defines ensure as “to make sure, certain, or safe: guarantee.”

When you look into the etymology — or word origin — of insure, you find that it entered English in the 15th century. It adds that the commercial sense of the word, which involves paying premiums to guarantee the safety or replacement of an item, came even later.

The dictionary provides two definitions for insure. The first reads, “to provide or obtain insurance on or for.” The second reads, “to make certain especially by taking necessary measures and precautions.” Both imply an act of either taking out an insurance policy or taking action to safeguard something.

The obvious way to distinguish the two is to consider the word insurance. If you’re going to take out a policy on something, you’re insuring it. If you want to be certain about something, you’re ensuring that outcome.

It’s a great reminder that you shouldn’t rely entirely on spell check.

Patrick is a Christian with more than 30 years experience in professional writing, producing and marketing. His professional background also includes social media, reporting for broadcast television and the web, directing, videography and photography. He enjoys getting to know people over coffee and spending time with his dog.