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Ensure vs. Insure (And Assure)—Grammar Guide (Examples)

Ensure vs. insure. These words sound very similar in pronunciation. And only separate themselves through one single letter. Although, what’s the difference between them? Do they hold different meanings?

Learn in this simple grammar worksheet…

ensure vs insure
Ensure vs. insure example.

Definition of “ensure”

The Cambridge Dictionary defines ” ensure” as “to make something certain to happen.”

Oxford Learner’s Dictionary, on the other hand, defines ‘ensure’ in these ways:

  • make certain that something will occur or be the case.
  • make certain of obtaining or providing something
  • make sure that something does not occur

As per Merriam-Webster, “ensure” is a transitive verb that means to “make sure, certain, or safe.”

Most other definitions of “ensure” are similar to these definitions. For instance, according to dictionary.com, the verb “ensure” means:

  • to guarantee or secure
  • to make certain or sure
  • to make safe or secure (from harm)

To sum up, to “ensure” something is to make sure that something is done or happens.

Ensure (verb) /inˈSHo͝or,enˈSHo͝or/make certain that (something) shall occur or be the case.
Insure (verb) /inˈSHo͝or/secure or protect someone against (a possible contingency).

Synonyms of “ensure” when used in the sense of “making sure something occurs or does not occur again,”

  • guarantee
  • assure
  • cinch
  • make certain 
  • secure 
  • confirm 
  • make sure
  • certify

When used in the sense of “protecting something”, the synonyms of ‘ensure’ include:

  • make safe
  • safeguard
  • protect 
  • secure 
  • guard 
  • defend

The etymology of the word “ensure”

The word “ensure” is derived from an Anglo-French term enseurer,” where “en” translates to “make” and “seur ” means “sure.” The usage of the word ‘enseurer’ can be traced to the late fourteenth century where Old French was being spoken in Northern France.

We use “ensure” to convey the same meaning as the word ‘enseurer‘ conveyed, which is to “make certain or sure.” “En,” as the word-forming element from Latin and Old French, conveys “in” or “into.”

ensure vs insure
Ensure vs. insure example.

“Sure,” is a word that comes from ‘sur‘ or ‘seur‘ in Old French which means “safe or secure.” Its origin can also be traced to the Latin word “securusmeaning “untroubled, free from care, or safe”

In the 13th century, ‘sure’ meant “firm or reliable” and came to mean “confident or mentally certain” in the mid-fourteenth century.

According to another source, the Anglo-Norman French word enseurer is probably a modification of the Old French term “aseurer, ” which is the origin of the word “assurer.”

Definition of “insure”

Here is the Oxford Dictionary‘s definition of “insure”

“arrange for compensation in the event of damage to or loss of (property), or injury to or the death of (someone)”

“secure or protect someone against (a possible contingency).”

“to buy insurance so that you will receive money if your property, car, etc. gets damaged or stolen, or if you get sick or die.”

ensure vs insure
Ensure vs. insure example.

The Britannica Dictionary defines “insure” in the following ways:

  • to buy insurance for (something, such as property or health)
  • to provide insurance for (something, such as property or health)
  • to make (something) sure, certain, or safe : ensure

According to Merriam-Webster, “insure” as a transitive verb means:

  • to provide or obtain insurance or
  • to make certain something happens by taking precautions

When used as an intransitive verb, “insure” means ” to contract to take or give insurance.”

Here is the definition of “insure” from Dictionary.com:

When used as a verb with object, it means:

  • to guarantee against harm or loss
  • to secure indemnity in case of damage, loss, or death.
  • to issue or procure an insurance policy for or on

When used without object, “insure” means to procure or issue an insurance policy.

The Collin’s English Dictionary defines ‘insure’ this way:

  • to guarantee or protect (against risk, loss, etc)
  • to issue (a person) with an insurance policy or take out an insurance policy (on)

Interestingly, ‘insure’ is used as a synonym for “ensure”, particularly in the U.S.

The synonyms of ‘insure’ include:

  • assure
  • cover
  • shield
  • safeguard
  • underwrite
  • hedge
  • protect
  • guard
  • indemnify
  • warrant
  • pledge
  • certify
  • promise
  • secure

The etymology of the word “insure”

Insure is a word derived from the mid-fifteenth century word “insuren” which is a different way to spell “ensuren.”

Ensuren comes from the Anglo-French word “enseurer, “which means to “make safe and secure.”

The word ‘insure’ acquired the commercial sense of “protecting against loss or harm by making premium payments” in the mid-seventeenth century.

As you can see, the confusion on using ensure vs insure comes from the fact that both the words come from the same French word “ensuren.”

In the mid-seventeenth century the word “insure” replaced “assure” to convey the commercial purpose.

ensure vs insure
Ensure vs. insure example.

What does it mean to “assure” someone

While the meanings of the words ‘assure,’ ‘ensure,’ and ‘insure,’ overlap in some contexts, the word ‘assure’ is particularly used to denote the removal of suspense or doubt from someone’s mind.

To assure someone is to give them confidence or certainty. It can also mean making sure they are safe or cared for.

If you are ‘assuring someone,’ you are telling them confidently that they need not worry because something is true or is guaranteed.

These examples bring out the meaning of ‘assure:’

  • The mechanic assured the customer that the latter’s car will be ready by Thursday.
  • The President assured the citizens that there will be no hike in taxes this year.
  • John assured Diana that the raft was safe to use.
  • “Let me assure you that your money is safe in the bank.”

Which spelling is correct, “ensure” or “insure”?

The answer is that both spellings are correct. You will need to use the correct word and spelling depending on the context.

British English clearly differentiates between ‘ensure’ and ‘insure.’ Insure in British English is used to typically denote “buying or providing an insurance policy.” Ensure is used to denote ‘ make sure something happens or occurs.”

However, in American English, ‘ensure’ and ‘insure’ are often used interchangeably. For instance, Americans may use ‘insure’ in place of ‘ensure’ like this:

“I will try to insure that you have a pleasant stay.”

ensure vs insure
Ensure vs. insure example.

The meanings of “ensure” (“to make sure”) and “insure” (“to make sure, especially by taking precautions”) are similar, insure has an additional commercial meaning.

This additional meaning is “to obtain or provide insurance” which is not conveyed by “ensure.”

Moreover, ‘ensure’ denotes a guarantee of something as in:

  • “The Governor ensured that the state was prepared for the storm.”

“Insure” on the other hand conveys the importance of taking necessary measures to safeguard against something as in:

  • “Careful planning will help insure your success.”

However, if you want to talk about buying insurance products to safeguard your assets or your health, the correct spelling is ‘insure.’ For example:

  • “I am looking to insure my home by buying an additional flood policy.”

In this sentence, the word “ensure” cannot be used.

Looking at some examples of the usage of ensure vs insure will provide more clarity on which spelling is right in specific contexts.

ensure vs insure
Ensure vs. insure example.

Examples of “insure” in sentences

In this section, we will look at how the word “insure” is used in sentences. The word “insure” in these sentences is used as a verb to mean make sure something will happen or to protect someone from harm.

Here are some examples to illustrate its usage:

  • The insurance company had to insure the painting for $10 million.
  • I can’t afford to insure my car.
  • We are insured by the company
  • I need to insure my house against fire.
  • If you’re not insured, then you’ll have to pay for the accident damages yourself.
  • Doctors recommend eating healthy to insure against illnesses.
  • Despite meticulous planning, there is no way to insure against natural disasters.
  • Insure your car and house to safeguard against emergencies.
  • The doctor insured herself against failure by not treating any complex illnesses.

Examples of “ensure” in sentences

Here, we will look at the usage of the word “ensure.” In all of these sentences, “ensure” denotes ‘making sure or certain that something happens.”

  • The company ensures that the customer is satisfied with their purchase.
  • The military took certain measures to ensure the safety of the refugees.
  • Sadie saved money to ensure she could buy the expensive car she wanted.
  • She ensured that her child was safe.
  • He ensured that the girl was happy.
  • The FDA’s regulations are designed to ensure the drug is safe for pediatric use.
  • If you want to ensure that you are going to be successful, then you need to work hard and do your best.
  • Vaccines ensure that we are protected from diseases.
  • As an instructor, it is my duty to ensure that every child learns how to swim.

How to remember which word to use

It is important to remember which word to use and when.

One easy way to remember is to:

  • Use ‘ensure’ when you want to make sure that something will happen.
  • Use ‘insure’ when you want to protect yourself against the risk of something happening.

Insure is the word that you need if you are looking for protection or coverage in case something goes wrong. Typically it is used in a financial sense (to insure against risks such as floods, illnesses, etc.).

Ensure means “to make certain” or “to guarantee.”

ensure vs insure
Ensure vs. insure example.

When to use “ensure”

Ensure is a word that is used to express the idea of making sure that something happens or expressing certainty that something will happen.

To mean “to make certain,” “to guarantee,” or “to make safe.”

“Please ensure that all the lights are turned off before you leave.”

In the sense of securing something from risk or danger.

Ensure is a word that can be used in the sense of securing something from risk or danger. For example,

“The government should ensure that there are enough police officers to protect the citizens.”

“Before going on a long drive, you need to inspect your car to ensure there are no problems.”

Show that something will happen or be done.

The word ‘ensure’ can be used to express a sense of certainty. It can also be used to express a sense of determination, guarantee, promise, or pledge that something will happen.

“His flawless record and extensive experience will ensure his career progress.”

When to use “insure”

The word “insure” is used in these contexts:

To provide a guarantee that something will happen or that something will be provided for future use.

” This crisis has shown us that we must insure against future uncertainties.”

To make sure of the safety of, as by providing against future danger, risk, or loss.   

For example:

“I insure my car against theft.”

“You can also insure yourself against a number of risks, such as accidents, natural disasters, and even the cost of living to a certain age.”

To denote that certain steps must be taken to guarantee something

“Careful planning is important to insure success.”

Common questions

Questions about “ensure” and “insure”

Is assure and ensure the same?

No. They hold different meanings. Insure refers to the financial service of insurance (or having the broader meaning of guaranteeing something). Meanwhile, “assure” (or the word “assurance”) means to dispels doubt. These three words can frequently get confused.

In the Commonwealth (British English), the use of “life assurance policy” is not uncommon.

Is it insure or ensure?

Most commonly, it’s ensure. These two words are frequently confused in the English language. Although, in the United States, these two words can get used interchangeably. The words “insure” and “ensure” are typically understood by American readers.


  1. ENSURE | meaning, definition in Cambridge English Dictionary
  2. Ensure Definition & Meaning – Merriam-Webster
  3. Ensure definition and meaning | Collins English Dictionary
  4. Ensure Definition & Meaning | Britannica Dictionary
  5. Ensure – Definition, Meaning & Synonyms – Vocabulary.com
  6. ensure | Etymology, origin and meaning of ensure by etymonline
  7. Insure Definition & Meaning | Britannica Dictionary
  8. INSURE | meaning, definition in Cambridge English Dictionary
  9. Insure Definition & Meaning – Dictionary.com
  10. 15 Synonyms & Antonyms for INSURE – Thesaurus.com
  11. Insure Synonyms | Collins English Thesaurus
  12. insure | Etymology, origin and meaning of insure by etymonline

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About the author

Dalia Y.: Dalia is an English Major and linguistics expert with an additional degree in Psychology. Dalia has featured articles on Forbes, Inc, Fast Company, Grammarly, and many more. She covers English, ESL, and all things grammar on GrammarBrain.

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