When two words are just one letter off from each other, it can be hard to tell them apart. It’s even worse if their meanings overlap. Take insure and ensure, for instance. Many people don’t know there’s any difference between them at all. They do have different meanings, but if you’ve been using them interchangeably, are you wrong?
As different as they are, their meanings do intersect on some counts. But how close are they? It’s a matter of contention between grammar lovers, whether to correct erroneous usage or not. Let’s take a look at when it’s better to insure and when something is ensured, and find out if there’s any case where you can use both.
The difference between insure and ensure is a recent development in the English language. It used to be nothing more than a spelling variation until the mid-19th century. At that time, linguists and language journals began to debate whether the two could really be called the same word. Ultimately a distinction was made.
Generally, to ensure means to make sure of something. You’d use this version when you want to exercise some control over a situation and guarantee a particular outcome. When you ensure something, you’re talking more about an event than an object. It’s more conceptual and involves creating a specific end result.
Meanwhile, to insure refers to insurance. It applies to finances and monetary coverage for personal belongings or tangible conditions. This means that only things with physical value can be insured — your house, your car, yourself. It talks about concrete objects as opposed to potentials.
Is there ever a time where you can use insure and ensure interchangeably? That’s still debated. You will see a lot of people using the two verbs in the same context whether it’s technically correct or not. It’s hard to say it’s wrong when language is so versatile and always adapting. After all, insure and ensure used to be no different than color and colour.
Today, most agree that there is an identifiable distinction, and therefore the two words are no longer interchangeable. Although their definitions are similar — creating assurance of something, whether monetary or in terms of outcome — their applications are separate enough that one doesn’t make sense in the place of the other.
If you insure someone will be happy with their purchase, that has nothing to do with compensation. Likewise, you wouldn’t say someone has ensurance on their home. It doesn’t make sense.
The bottom line is, the difference is subtle enough you may get away with using the wrong word in verbal conversation, but you'll want to brush up on the correct usage when writing.
Will you be penalized if you don’t use the right version? That depends on the context. In daily conversation, probably not. For an English paper or a published article? Definitely. Still, there are many intelligent people in various fields who don’t know the difference, and you have a good chance of sliding under the radar if you make this mistake.