Ensure, assure and insure: a trio of verbs that not only sound similar, but are also closely related in meaning. Let’s see how these words work in English, their correct usage, and more.
“Ensure”, “assure”, and “insure”
| Meaning | Examples |
|---|---|
| assure [verb] to say confidently that something is true | We were assured that everything possible was being done. |
| ensure [verb] to make certain something will happen | The system ensures equal access to education for all kids. |
| insure [verb] to guarantee or protect against loss or harm | The car is insured against fire and theft. |
She assured me that the meeting would start on time.
We must ensure the success of the project.
The new policy will assure equal access for all students.
Wearing a seatbelt helps to insure your safety in a car crash.
Are ensure, assure and insure interchangeable?
- Ensure means “to make something certain to happen: The company’s sole concern is to ensure the safety of its employees.“
- Assure means “to tell someone confidently that something is true: She assured him that the car would be ready the next day.”
- Insure means “to guarantee against loss or harm”, or “to provide or obtain insurance”. Example: The house is insured for two million dollars.
To insure is to “guarantee against loss or harm”, or, specifically, “to cover with insurance”. Ensure and insure are frequently confused with each other, since both words have to do with making a guarantee or making certain of something. The difference is that to insure relates more to things of a financial nature, such as insurance. To ensure is more broadly applicable and just means to make sure or certain of something.
Ensure is to “to make sure, certain, or safe”, but without the financial connotation that insure has in protecting against possible loss. This makes the verb ensure more general in application and use, e.g., ‘Please ensure that the doors are locked when you leave‘.
To assure is to tell someone something with confidence so as to reassure or convince them of that thing (usually so that they don’t worry about it). In fact, assure is synonymous with reassure, or words like convince, persuade, and so on. Assure is not quite about making certain something will happen (which is to ensure), but to inspire confidence in another person of something.
“Insure”, used in sentences
| Examples: “insure’ used in sentences |
| He decided to insure his new car against potential accidents and damages.
The business owner knew the importance of insuring the company’s assets to safeguard against unexpected losses. She wanted to insure her valuable art collection to protect it from theft or damage. The insurance company offered a policy that would insure the traveler’s belongings during their vacation. It’s wise to insure your home against natural disasters like floods and earthquakes. |
“Ensure”, used in sentences
| Examples: “ensure’ shown in sentences |
| Please ensure that all doors are locked before leaving the building.
The chef took extra care to ensure that each dish was prepared to perfection. The company implemented strict security measures to ensure the safety of its employees. Double-check your work to ensure that there are no errors before submitting the report. The project manager worked tirelessly to ensure that the project was completed on time. |
‘Assure’, used in sentences
| Examples: “assure’ shown in sentences |
| She assured her friend that she would be there to support her during the difficult times.
The company’s CEO personally assured the employees that their jobs were secure despite the restructuring. The doctor assured the patient that the procedure was safe and well-tested. The teacher assured the students that there would be no pop quizzes that week. He assured his parents that he would take his studies seriously and improve his grades. |
Link the first letter: **A** for **A**ssure (person), **E** for **E**nsure (outcome), **I** for **I**nsure (insurance).
Synonyms of insure/assure/ensure
Synonyms of insure:
- underwrite
- guarantee
- shield
- cover
- assure
- hedge
- safeguard
- warranted
Synonyms of ensure:
- confirm
- secure
- guarantee
- verify
- check
- certify
- corroborate
- make sure
- make certain
- see to it
- establish
- set the seal on
Synonyms of assure:
- reassure
- convince
- satisfy
- persuade
- guarantee
- pledge to
- attest to
- prove to
Origin of insure
Mid-15c., insuren, spelling variant of ensuren “to assure, give formal assurance” (late 14c.), also “make secure, make safe” (c. 1400).
Origin of ensure
Late 14c., from Anglo-French enseurer, from en- “make” (see en- (1)) + Old French seur “sure” (see sure); probably influenced by Old French asseurer “assure.” Compare insure. Related: Ensured; ensures; ensuring.
Origin of assure
Late 14c., “reassure, give confidence to; make secure or safe, protect; bind by a pledge, give a promise or pledge (to do something),” from Old French asseurer “to reassure, calm, protect, to render sure”, from Latin *assecurar, from ad “to” (see ad-) + securus “safe, secure” (see secure (adj.)). Related: Assured; assuring.
Other commonly confused words
Sources
- Harper, Douglas. “Etymology of insure.” Online Etymology Dictionary, https://www.etymonline.com/word/insure. Accessed 13 August, 2023.
- Harper, Douglas. “Etymology of ensure.” Online Etymology Dictionary, https://www.etymonline.com/word/ensure. Accessed 13 August, 2023.
- Harper, Douglas. “Etymology of assure.” Online Etymology Dictionary, https://www.etymonline.com/word/assure. Accessed 13 August, 2023.
Work Sheet
According to the post, which word is used when confidently telling something to a person to convince or reassure them?
Which word, according to the blog post, means “to make certain something will happen”?
The post states that this word relates to financial protection against loss or harm:
Which of the following sentences uses the word “assure” incorrectly, based on the blog post?
Based on the post, which word would be most appropriate if you are NOT talking about financial protection, but just making something certain or safe?
She looked worried, so I tried to her that everything would be okay.
We need to the success of the event by planning carefully.
Did you remember to your new laptop against theft?
Please that all the windows are closed before leaving.
The doctor the patient that the procedure was completely safe.
Frequently Asked Questions
What does the word “assure” mean?
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When is “ensure” the correct word?
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How is “insure” different from “ensure”?
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Can I use “assure” for an outcome?
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Does “ensure” imply financial protection?
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Yash, D. "The Difference Between “Ensure”, “Insure” and “Assure”." Grammarflex, Jun 15, 2025, https://www.grammarflex.com/the-difference-between-ensure-insure-and-assure-explained-examples/.
