I've talked about assure, ensure, and insure in the past, but I think these supremely confusable words deserve a reprise.
Assure--to tell someone not to worry, is the way I think of it, as in the word reassure. This is also the word that the term quality assurance is based on. Here, I think of it as a process that allows a company to assure customers that the product is of high quality.
The postal clerk assured me that the package would arrive on time.
Ensure--to make sure or to make certain. This verb is the one you want when you ask a student to double-check something:
The clerk ensured that the correct zip code was printed on the label.
Please ensure that the checkbox is selected, then click the OK button.
Insure--You are safest in usage on this one if you are talking about purchasing insurance. However, the U.S. military tends to use this also as a synonym for ensure.
All of the specific usage I am discussing here goes beyond what descriptive dictionaries, such as Merriam Webster's, indicate. I found their differentiation of these terms to be too vague, compared with the standards I have typically been asked to follow when doing professional copyediting. So to be precise, make the distinctions indicated here.
Here's a second set of confusing words: comprise/compose/constitute.
Comprise--just memorize that the phrase is comprised of is always wrong. The larger thing comprises the parts, or draws them together:
The monument comprises a stone obelisk and a colonnade.
Compose--to make up. Is composed of is correct:
The monument is composed of two parts: a stone obelisk and a colonnade.
This Week's Challenge: Which is correct?
- We ensured/insured the ring for $3,000 after the jeweler apprised/appraised its/it's value.
- He told the participants to ensure/insure that their computers were logged out after the class.
- He also ensured/assured them that their files would not be erased.
- The new app is composed of/is comprised of two parts.
- The new app composes/comprises two separate parts, both of which are better than/then competing online services.
- Ensure/insure/assure that the dialog box is closed before exiting the program.
- The training program is comprised of/is composed ofdemonstrations, exercises, and quizzes.
- The individual programs of which the suite is comprised/of which the suite is composed/which the suite comprises are also available as stand-alones.
Feel free to post your answers below as comments.