Ensure vs. Insure vs. Assure: What’s the Difference?

The words ensure, insure, and assure are often confused with each other in English and leave people wondering which one is correct. And not without reason. It’s easy to gloss over these words in conversation because they all sound very similar when spoken. Plus, they’re only a few letters apart from each other, which adds to the confusion.

What are the Differences Between Ensure, Insure, and Assure?

Today, I want to clear up that confusion and outline the unique characteristics of each of these words. I will cover the functions, definitions, and grammar behind each word, so you can understand their differences and use them properly.

After reading this post, I can assure you will never misuse ensure vs. insure vs. assure again.

To start, all three words come from the Latin securus, meaning to make safe or to make sure. This is in part why they are so tough to keep apart, because they come from the same word and still have very similar meanings. All three words share an element of making an outcome certain, but they are used at different times and for different things.

When to Use Ensure

define-insuring-vs-ensuringEnsure is a transitive verb meaning to make certain or guarantee. To ensure is to make sure that something will (or won’t) happen or be the case. For example,

  • The sunscreen I applied ensures that I will not burn.
  • You must take the proper precautions to ensure your privacy.
  • To ensure that we don’t run out again, I ordered more food.

What makes ensure different from the other words is that we only ensure events or states of being; we don’t ensure things. This means that we ensure that we can get time off from work, but we don’t ensure our car.

When to Use Insure

Insure is also a transitive verb meaning to protect oneself financially by insurance. Insure, in best usage, is reserved for underwriting financial risk. For example,

  • The company insured itself against losses by diversifying.
  • You should insure your house against theft.
  • Is your car insured for the full amount?

Unlike ensure, which applies to events, insure applies to things. So we insure our house, our car, and our business.

When to Use Assure

Assure is a transitive verb meaning to inform positively to remove doubt. For example,

  • The attendant assured us the flight was on schedule.
  • I assure you nothing is wrong.
  • Your kindness assured me of your devotion.

In most senses, we assure people that their concerns are being addressed.

Practice Quiz and Examples

Below are a few sentences you can use to practice,

  1. Greg ______ me we were going in the correct direction.
  2. This table should be ______ for at least $3,000.
  3. In order to ______ a pleasant trip, we ask for your cooperation.
  4. My colleague ______ me that he ______ the accounts, ______ that we were in the clear.

Display the answers below

Remember the Difference

A good way to remember ensure is that it has two “e’s” in it, just like guarantee does. To ensure is to guarantee.

You can remember insure because it deals with finances and underwriting risks. You generally do this taking out an insurance policy. Both words start with insur.

Assure is something that you tell to another person, something that can feel doubt or uncertainty. This means you only assure things that are alive. Both start with an A.


All three of these words are used in specific instances, so it’s important to keep track of insure vs. ensure vs. assure.

Ensure is to make certain or guarantee. You ensure events and states of being.

Insure is to protect yourself from financial risk. You insure things like cars or homes.

Assure is to tell someone something positively or confidently to remove any doubt.


  1. Assured
  2. Insured
  3. Ensure
  4. Assured, insured, ensuring


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