Insure, ensure and assure are easily confused words as they both look and sound similar – and have rather closely connected meanings. They do have distinct differences, however. Consider the following example sentences:

• We would like to insure our boat for £10,000.
• I will ensure that the boat is taken care of.
• I assure you the boat will be taken care of.

So how are these sentences different?

What are the different meanings of insure, ensure and assure?

To start with, let’s look at the basic uses of these words. As verbs, they are most commonly used for the following actions:

• Insure – arranging compensation against future damage / to secure or protect against something
• Ensure – making certain something will occur
• Assure – communicate positively, to remove doubt

Therefore insure is mostly used talking about technical compensation (monetary for example, such as referring to arranging house or object insurance); ensure is used to guarantee a future event (similar to the more informal form of ‘make sure’); assure is mostly used to convince someone of a truth. It can be helpful to consider the related nouns insurance (monetary compensation) and assurance (confidence, or a declaration of confidence). Note that ensurance, however, is not used as a noun!

• Our home insurance policy paid us £25,000 after the fire.
• We have had assurance from the station that the train will arrive on time.

Areas where insure, ensure and assure are commonly confused

There are two major problems with these words that make them difficult to separate, however. Firstly, insure is often used in American English to mean ensure – making the words interchangeable, depending on where you are! However, this does not work the other way – ensure is not used to mean arrange compensation.

Secondly, assure can be used in many situations in exactly the same way as ensure, to mean to make sure of something. This is particularly interchangeable in the passive tense.

• We assured a positive welcome. / We ensured a positive welcome.

There is also cross over in the nouns, insurance and assurance, as assurance can be used in technical language (such as in financial assurance or life assurance) to have a similar meaning to insurance. In the case of life assurance, this denotes a type of insurance with payments made over a period of time. Grammatically, you may see it used in a sentence in exactly the same way as insurance.

Any questions, please feel free to get in touch – and if you found this useful be sure to check out my growing list of common areas of confusion in English.