Some of the most painful writing lessons I have learned came under the tutelage of my 11th grade English teacher, Mr. Perkins. He was a tough nut — whenever a writing assignment was submitted, you would receive two grades. The first grade would score content, the second scored grammar and punctuation.

I remember seeing plenty of 90/10 grades as Mr. Perkins took off a full ten points for every grammatical and punctuation error. Was that fair of him? Probably not, but what it did do for his students was to force us to pay extra special attention to our work. I think I ended up getting a “D” for the class, not a particularly good grade for someone who was trying to build up his writing confidence.

Decades later I still have my struggles, but they are comparatively minor and easily overcome especially when I take the time to review what I have written. Are you hassled by grammar gremlins and their punctuation pals? Let’s take a look at some grammatical mistakes worthy of an exorcism:

Exorcise v. Exercise — Admittedly, I rarely see the word exorcise used. I just wanted to highlight a word I placed in my title and mentioned in my opening paragraphs. Exorcise means to remove evil spirits while exercise is the body movement too many couch potatoes avoid. Worth Noting: I have seen exercise spelled excercise, which is incorrect.

Your v. You’re — This mistake crops up all of the time. Use your when discussing what someone possesses, e.g. your cat, your job, while you’re is a contraction of you are.

i.e. v. e.g. — I won’t get into the Latin meaning for these two widely used abbreviations, but i.e. means “that is” while e.g. means “for example.” There are times when either Latin abbreviation could be used in a sentence, but what is being conveyed is quite different.

Center around v. Center on — How can you center around anything? You cannot. You can center on or focus on something, but not around it. Think about it!

Lose v. Loose — This mistake keeps rearing its ugly head. If you lose something, that item is missing. If you loose something, you have let something go.

Less v. Fewer — This is my most insidious gremlin. Use less as you would use much; use fewer as you would use many. Remember this rule: Less/much is for noncount nouns while fewer/many is for count nouns.

Than v. Then — I believe I have all but vanquished this gremlin, but I wouldn’t be surprised if someone uncovered this mistake in some of my earlier writings. Than is used for comparative purposes such as, “I like apples more than oranges.” Then is used for conveying time — “Back then, we used typewriters for report writing.”

There are many more grammar errors not mentioned herein which are worth subduing the moment they rear their ugly heads. Even the most experienced writer can slip up, but catching grammatical errors before publishing will quickly cast out the dirty devils before they have an opportunity to make you look foolish.

Mr. Perkins was my worst nightmare way back when, but I have to believe the tough lessons learned ultimately have been more helpful than hurtful.