• 3-minute read
• 18th August 2015

Word Choice: Assure, Insure or Ensure?

There are lots of English words which look similar to one another but diverge in meaning, often causing problems for those learning the language. But the trio of ‘assure’, ‘insure’ and ‘ensure’ even confuse native speakers from time to time.

This confusion arises because all three words are verbs derived from the Latin securus, meaning ‘safe’ or ‘secure’. The terms ‘assure’, ‘insure’ and ‘ensure’ all therefore relate to the idea of securing something. But there are important differences in what they mean.

Understanding these differences will help you to communicate your ideas more clearly, both in your academic writing and in day-to-day life. To help out, we’ve prepared this handy guide about how they should be used.

Assure (Setting Your Mind to Rest)

To ‘assure’ means to remove doubt or give confidence about something:

Dr Laverne spoke in serious tones, but she also assured Gerald that he’d be okay.

It can also mean to make something certain:

Victoria knew she’d be assured the win when she scored in the next round.

One helpful tip here is to remember that ‘assure’ starts with the same letter as ‘alive’, since only things which are alive (and capable of feeling doubt or anxiety) can feel ‘assured’.

Ensure (A Guarantee)

To ‘ensure’ something is to take precautions to guarantee it:

Oliver set his alarm for 6:30 AM to ensure he’d be ready for the long journey ahead.

‘Ensure’ has a very broad application and can be applied to living things, events and objects:

Its aluminium cutting deck ensures that the new Honda lawnmower can handle even the toughest jobs.

This word is therefore basically a synonym for ‘guarantee’ or ‘make certain’.

Insure (Financial Protection)

Finally, the term ‘insure’ typically implies guarding against financial liability. Health insurance, for example, is a contract you enter to cover unexpected expenses arising from illness or injury. To ‘insure’ something is therefore usually to take out an ‘insurance policy’:

It is important to insure your property against fire, theft and third party damage.

It’s perhaps worth noting here that, in Britain, some people refer to ‘life assurance’ instead of ‘life insurance’ (i.e. an insurance policy which insures against death). This is fairly uncommon, though, with ‘insurance’ now the more widely used term.

Assure, Ensure or Insure?

These terms can be tricky if you’re not used to them, but once you understand how they differ it’s fairly simply to tell them apart:

Assure = Ease doubt/worry (of a living thing)

Ensure = Make something certain

Insure = Protect against financial loss

If you can do this, you should now feel a bit more ‘assured’ about communicating your ideas clearly and effectively.