Ensure, Insure, and Assure: Clearing up a Classic Triple Mix-Up

Ensure, Insure, and Assure: Clearing up a Classic Triple Mix-Up
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One of my favorite things about being a writer is exploring the nuances of language — combing through my own vocabulary or a dictionary to find the word that perfectly encapsulates what I am trying to say.

This can get tricky, however, when words that have similar meanings also look and sound similar. I frequently see writers mix up the words insure and ensure, and assure is similar enough to these that it also adds to the confusion.

To avoid future mix-ups, let’s take a look at those nuances that make us double- and triple-check these three words.

Ensure vs. insure vs. assure — what’s the difference?

Ensure, insure, and assure all have relatively similar meanings, but each one is better suited for some purposes than others. For a long time, they were interchangeable words, but these more specific definitions and uses were assigned in the mid-19th century to relieve some of the confusion.

Ensure vs. insure vs. assure — what's the difference?


Ensure means to secure or guarantee something or to make something certain. I find that this is most often the word that people are looking for when they accidentally substitute one of the other two. If you ensure something, you are guaranteeing that it will happen.


He was positive that his excellent grades and stellar personal essay would ensure his admission to the university.


They put down a deposit on the apartment, ensuring that the landlord would not rent it to someone else.  

Ensure vs. insure vs. assure — what's the difference?


Insure also has to do with guaranteeing something, but it specifically refers to guaranteeing it against loss or harm, or to issuing or obtaining an insurance policy. This definition means that uses of insure are much more specific than uses of ensure or assure. Unless your conversation could include State Farm or Progressive, you might want to opt for one of the other possibilities.


Because we live on the coast, we have to insure our house against hurricanes and other natural disasters.


My dad said that it was important to do research about insuring my car before I bought it.

Ensure vs. insure vs. assure — what's the difference?


Assure is a transitive verb, meaning that it is used with an object. It can mean quite a few things: to state with confidence to someone, to cause to know surely, to promise, to secure, or to encourage. While assure is similar in definition to ensure, its use with an object means that is something you do to someone or something. You might assure someone that everything will be OK or assure your boss that you will complete a project by the deadline.


She assured her mom that she would be home by curfew on prom night.


His contract assures him a job at the company for at least five years.

In summation: to ensure is to make something certain, to insure is to protect something from harm, and to assure is to promise something or to state something with confidence to someone.

Because the differences between these words exist mostly in how they are used in context, it’s possible to use all three in a single sentence.


She assured her husband that her new job would ensure their ability to insure their house against any and all unforeseen circumstances.

You insure a house, you ensure an outcome, but you assure your friend. They might have similar definitions, but it's important to know the distinctions that inform the different uses of ensure, insure, and assure. #writing #editing #contentmarketing Click To Tweet

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About the author

Cassie LaJeunesse

Cassie LaJeunesse is doing everything in her power to prove wrong the people who scoffed at her English degree. A former college newspaper editor, she now writes and edits content for a regional magazine. She also finds time to freelance for her alma mater and other publications, writing and editing in a variety of styles and subjects. Now that she has completed her degree, she uses her free time to read as much as possible, sing in a choir, and hang out with her cat, Gilbert.