Several words in the English dictionary often confuse even native English speakers in terms of their usage. One such pair is “assure” and “ensure”.
Although both words have been derived from the Latin word “securus”, which means “safe,” both cannot be used in the same context or in place of each other.
Key Takeaways
- Assure means to give confidence or a guarantee to someone about something.
- Ensure means to make sure that something happens or is done correctly.
- Assure focuses on providing confidence or a guarantee, while ensuring focuses on ensuring something happens correctly.
Assure vs Ensure
The difference between “assure” and “ensure” is that the basic meaning of “assure” is to inform a person confidently about something that is indeed true, in order to prevent the person from worrying about it. For example, “The CEO assured his employees that their jobs are secure.” Ensure means to make sure something will happen. For example, “The airline has taken proper steps to ensure timely departure and arrival of all their flights.”

It will not be wrong to say that assurance is used when you wish to make a kind of promise to another person with regards to something in order to help the other person overcome doubts or anxiety. You may say that ensure is used when you wish to make sure that things will either happen or not happen, irrespective of any situation.
Comparison Table
Parameter of Comparison | Assure | Ensure |
---|---|---|
Definition | It is a promise to a person about a situation or something in order to gain his trust and to get rid of any worries or doubts in his mind. | It is a type of guarantee to someone in terms of something that will indeed happen or not happen, no matter what the situation is. |
Refers to | It refers to a person. | It refers to a situation. |
Used to | Assure is mainly used to relieve someone of his doubts or to convince someone about something. | Ensure is mainly used as a guarantee to a person about something that will indeed either happen or not happen, irrespective of the situation. |
Example | She assured me that she would never cheat during her exams. | I assure you that your child will be delicate with us. |
What is Assure?
If you want to put it in simple words, “assure” is used in situations wherein you need to get rid of a person’s doubts. For example, your child may think that he will not be allowed to play out with his friends once he returns from school.
In such a case, you can convince him and clear his doubt by saying, “I assure you that you will be allowed to play once you finish your homework.”
When it comes to the origin of the word, assure, there are different views on the topic. Some believe that it derived its existence from the old French word “asseurer”, which means to calm, render, protect, and reassure.
On the other hand, some believe that it is derived from the old Latin word “assecurar”, which means safe and secure.

What is Ensure?
When you use the word ensure, you practically use it as a word of guarantee pertaining to the happening or non-happening of an event, irrespective of the conditions.
For example, when you wish to convey a new rule to your employees, you say, “there is a new set of rules that have been implemented by the company in order to ensure that all staff members arrive to work on time.”
As far as the origin of the word “ensure” is concerned, it is said that it is derived from the Anglo-French word enseurer. The “en” in the word means “make”, and the “seur” means “sure.”
The word “ensure” was introduced in the English dictionary after the word “assure” was introduced.
In this modern era, it is widely used to bear the action of either guaranteeing or securing a specific development or result.

Main Differences Between Assure and Ensure
- Assure is used to get rid of any doubts or worries from another person’s mind by committing to an event or a situation that is bound to happen or not happen, no matter what the situation is. However, ensure is used as a verb in situations that state when something may or may not occur.
- Assure is used as a promise to someone. You assure someone that something will happen or will not happen. On the other hand, ensure it is used in a situation that may or may not happen.
- Although both assure and ensure are derived more or less from similar origins, “assure” was introduced to the English dictionary before “ensure” did.


Emma Smith holds an MA degree in English from Irvine Valley College. She has been a Journalist since 2002, writing articles on the English language, Sports, and Law. Read more about me on her bio page.