How do we make some thing or event certain? Do we assure it, ensure it, insure it, or secure it? It depends, but I assure you that you’ll be better able to pick the right word after reading this post.
In short, you insure against some event occurring or not occurring, you ensure some event occurs or doesn’t occur, you assure others that the event will or will not occur, and you secure yourself or your property to prevent harm from some event from occurring.
Assure is best used when you’re convincing someone else of something or promising them something.
- I assure you that we’ll meet the deadline.
- I was assured the check had been mailed.
Ensure implies that action is being or has been taken to achieve that certainty.
- I reviewed progress with the team leads to ensure the deadline would be met.
- Accounts Payable ensured the check was mailed.
Insure refers to mitigating the risk of something happening or not happening. This typically involves an insurance policy that calls for payment or reimbursement under certain conditions.
- We bought liability coverage to insure us against missing the deadline.
- The product was sent by insured mail.
We secure something by taking action to prevent or mitigate an attack or loss.
- We secured the building with an alarm system.
- She diversified her portfolio to secure her investments.
Secure can also refer to gaining possession of something.
- I secured a job.
- The police secured a confession.
And as an adjective, secure refers to being confident or safe.
- He was secure in his belief.
- It’s a secure facility.
I should note that dictionaries’ definitions of these words can overlap. For example, Merriam-Webster Unabridged lists senses for assure that reference ensure, insure, and secure. The Oxford English Dictionary lists some of these same senses but has marked them as obsolete. Using assure in those cases may cause the reader to stumble and wonder about the author’s word choice.
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