When is it appropriate to use assure vs. ensure vs. insure?

  • Excellent question... can't believe I didn't think of this one myself, because I've wondered the same thing countless times!
    – Jagd
    Commented Aug 11, 2010 at 23:30
  • yea, every time I have to use 'assure' or 'ensure', I always second-guess my choice. Definitely favorite-ing this question.
    – user13757
    Commented Mar 17, 2012 at 23:17

3 Answers 3


Assure: promise, as in I assure you the car is safe to drive.

Ensure: confirm, as in Ensure that you have plenty of gas in the tank before going on a long trip.

Insure: protect with an insurance policy, as in Insure the car before your trip.

  • 59
    I assured him that I ensured the car was insured.
    – Gary
    Commented Aug 11, 2010 at 0:12
  • 7
    This is a nice distinction to make and I wish everyone made it, but in practice, especially in American usage, the word "insure" is also often used (in addition to its financial meaning) in the same sense as your "ensure". Commented Aug 11, 2010 at 2:08
  • 1
    I think assure you can also be used in the senses of ensure and insure, although the whole word is a bit archaic. Note that there are a lot of "Assurance" companies throughout the English-speaking world. Commented Aug 11, 2010 at 9:03
  • 2
    There is a technical difference between insurance and assurance - IIRC insurance is against a risk (accident) assurance is against something that will happen (life assurance)
    – mgb
    Commented Apr 13, 2011 at 1:52

To “assure” a person of something is to make him or her confident of it. According to Associated Press style, to “ensure” that something happens is to make certain that it does, and to “insure” is to issue an insurance policy. Other authorities, however, consider “ensure” and “insure” interchangeable. To please conservatives, make the distinction. However, it is worth noting that in older usage these spellings were not clearly distinguished.European “life assurance” companies take the position that all policy-holders are mortal and someone will definitely collect, thus assuring heirs of some income. American companies tend to go with “insurance” for coverage of life as well as of fire, theft, etc.

"assure" Definitions:

  1. (v) make certain of
  2. (v) inform positively and with certainty and confidence
  3. (v) assure somebody of the truth of something with the intention of giving the listener confidence
  4. (v) be careful or certain to do something; make certain of something
  5. (v) cause to feel sure; give reassurance to
  6. (v) make a promise or commitment

"assure" Usages:

  1. Soon the Great Depression in the 1930s showed that democracy could not assure prosperity either, and the totalitarian creeds gathered momentum.
  2. In all of these markets, reform must assure transparency, prevent abuse, and protect the public interest.
  3. Conversely, oil companies might sell futures contracts to assure a profit against future price drops.

"ensure" Definitions:

  1. (v) make certain of
  2. (v) be careful or certain to do something; make certain of something

"ensure" Usages:

  1. Senator Bordallo has been fighting to ensure that the people of Guam have a voice in Washington.
  2. To ensure that as many Democrats as possible can cast their votes.
  3. While we do not know all the details of this arrangement, the Fed must ensure that the plan protects the families that count on insurance.

"insure" Definitions:

  1. (v) be careful or certain to do something; make certain of something
  2. (v) make certain of
  3. (v) protect by insurance
  4. (v) take out insurance for

"insure" Usages:

  1. AIG generally sells credit-default swaps, thereby promising to insure others against defaults.
  2. Some facts about 1944 movie tastes, as registered at the nation's box-offices: A popular star does not insure a popular picture.
  3. Say you buy a house and insure it.

Source: BeeDictionary


It is very easy to understand and remember the meaning and difference.

To assure someone is to remove someone’s doubts.

To ensure something is to make sure it happens—to guarantee it.

To insure something or someone is to cover it with an insurance policy.

Thank you!

Source: https://www.grammarly.com/blog/assure-ensure-insure/

  • +1. And I think the usage of insure can be used in the senses of ensure (in American usage).
    – haha
    Commented May 18, 2018 at 1:00

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