In, En, As: A Grammar Lesson

It’s been far too long since I attempted to make you all more proficient in the English language by posting grammar tips, so today I’d like to offer some wisdom on the importance of choosing the right vowel. The vowels in question are A, E, and I, when used in combination with one other letter to begin a word whose root is sure. (Bookmark this blog post, as you’re going to want to refer to it again and again in the future.)

Three words frequently get confused in our communication:

1. Insure
2. Ensure
3. Assure

The first two are homophones, meaning they sound alike but are spelled differently and have different meanings. Consequently, they are confused in written form, generally by writing “insure” when “ensure” is the appropriate word. The latter two have similar but nonetheless distinct meanings, and are confused in both written and spoken communication. Generally speaking, you insure things, ensure situations or outcomes, and assure people. Of course there are always nuances, but that is a good general rule of thumb to follow when in-doubt.

Below are the correct meanings and usages of these three cousins.

1. Insure. This word means “to provide insurance for something,” e.g. a house, car, fur coat, record collection, life, etc. Notice that the IN at the beginning of the word “insure” matches the IN at the beginning of the word “insurance”—which is how you can tell whether you’re using it correctly. Here are some examples:

CORRECT USAGE:
-- I want to insure my house against damage from floods and tornadoes.
-- Virginia state law requires drivers to insure new vehicles at the time of purchase. (Don’t quote me in legal circles on the accuracy of that statement.)
-- Michael Feinstein’s hands are insured for one million dollars. (See above note re: accuracy.)

INCORRECT USAGE:
-- I should verify Virginia state law to insure the statements on this blog are legally true. (Correct word: ensure.)
-- Tour de France winner Alberto Contador is regularly tested for doping to insure he won the race fairly. (Correct word: ensure.)
-- I will insure you understand this grammar principle by writing this clever post. (Correct word: ensure.)

2. Ensure. This word means “to make certain,” or “to guarantee.” Some examples of correct usage are:

CORRECT USAGE:
-- Following the grammar principles presented in this blog will ensure you use these three words correctly from now on.
-- I must leave work on-time today to ensure I won’t be late for Pool Talk.
-- This life jacket ensures that I won’t drown in the ocean, although it is useless in protecting me against sharks.

3. Assure. This word means “to make someone feel sure or certain”—not to actually guarantee the outcome of an action or situation. Here are some examples of correct and incorrect usage:

CORRECT USAGE:
-- The motto of the USPS assures its customers that the mail will be delivered in all types of weather.
-- Let me assure you that the grammar principles presented in this blog post are true, even if some of the statements are not.
-- The judge would not release me on bail until I assured him I would no longer violate the restraining order by stalking George Clooney.

INCORRECT USAGE:
-- Following all the assembly directions will assure that your Ikea table is put together perfectly. (Correct word: ensure)
-- I left work early to assure I would be on-time for Pool Talk. (Correct word: ensure)

I sincerely hope this post has proved enlightening and entertaining. Rest assured that the grammar principles outlined here will serve to insure your future communication against errors; following these precepts ensures you will never use these words incorrectly again. That's a lot of certainty in one blog entry.

PS A special shout out to Lindi for saying she loves my grammar posts and motivating me to write this one. Thanks, Lindi!