assure

Assure usually means to tell someone something with confidence or to cause someone to know something with certainty—it often means the same thing as reassure. Ensure most commonly means to guarantee or make certain, as in Working hard ensures success. Insure typically means to guarantee against loss or harm or, more specifically, to cover with insurance.

It’s no wonder there’s confusion between the three words—all three are verbs that are based on the Latin root sēcūrus, meaning safe. Making things even more confusing is the fact that ensure and insure can be used interchangeably in most senses. Still, insure is much more commonly used in the context of insurance, like car insurance, health insurance, and homeowner’s insurance. These kinds of insurance insure you—they give you coverage that provides you with compensation in certain cases and situations.

Ensure is typically used in a more general way in the context of actions that are done to make sure that something happens or is the case, as in We need to ensure that the meeting starts on time.

Assure is always used in the context of communication, especially in situations in which someone is trying to make someone else feel better about something. It’s used in the phrase rest assured.

Here’s a quick cheat sheet to remember the most common uses of each word:

assure = reassure
ensure = make sure
insure = cover with insurance

Here’s an example of assure, ensure, and insure used correctly in a sentence.

Example: She assured me that the company has ensured that every employee has the opportunity to be insured.

Want to learn more? Read the full breakdown of the difference between assure, ensure, and insure. 

Should assure, ensure, or insure be used in the following sentence?

We need to take action to _____ that this never happens again.