Ensure, insure and assure are three simple words that are often abused.
Ensure means to make sure. It is a good word, but it tends to be overused. Many writers like to place it before most of their verbs.
If you want to attend the conference, please ensure that you inform Martha Jones so she can submit your name.
However, what is it you really want? Do you want the reader to make sure he or she does it, or do you want him or her to actually do it?
If you want to attend the conference, please inform Martha Jones so she can submit your name.
Note: Busy readers prefer short, to-the-point sentences.
Insure means to provide insurance. It is not interchangeable with ensure.
How can you insure yourself against identity theft?
Assure is to remove worry or uncertainty.
I assure you that the operation is painless.
I assure you that if you ensure your word choice is correct, then it is not likely you will have to insure yourself against job loss.