Five Grammar Mistakes

Are your grammar skills rusty? Are you one of the people who never liked English in the first place?
Help is available! Work on these common mistakes, and you’ll soon see a big improvement in your writing.
Here are Mistakes 1 – 5. (Click here to see Mistakes 6 – 10.)

1.  Not ending sentences with a period.
Here’s a quick lesson: Extra ideas end with commas.
Sentences end with periods.

When McKay asked for a backup, EXTRA IDEA
McKay asked for a backup. SENTENCE
While I was driving to the scene, EXTRA IDEA
I was driving to the scene. SENTENCE

Here’s how to put extra ideas and sentences together:

When McKay asked for a backup, Jackson responded. CORRECT
While I was driving to the scene, I had a flat tire. CORRECT

2.  Not knowing what a sentence is.
Here’s a quick lesson: A sentence begins with a person, place, or thing.

He ran out the door. SENTENCE
After he ran out the door, EXTRA IDEA

It’s a sentence even if it’s short or unclear.

I understand. SENTENCE
It is here. SENTENCE

For more help with commas, go to Commas Made Simple and study Rule 1.

3.  Using a comma to start a new sentence with it. Nope! Use a period.

The rope broke, it wasn’t strong enough.  INCORRECT
The rope broke. It wasn’t strong enough. CORRECT
I rejected her explanation, it didn’t make sense.  INCORRECT
I rejected her explanation. It didn’t make sense. CORRECT

4.  Getting pronouns mixed up (I, me, he, him, she, her, we, us, they, them).

Jim and me searched the neighborhood.  INCORRECT.
(Think: I searched the neighborhood.)
Jim and I searched the neighborhood. CORRECT

The captain gave Cynthia and I a special assignment.  INCORRECT
(Think: The captain gave me a special assignment.)
The captain gave Cynthia and me a special assignment. CORRECT

For more help with pronouns, go to Pronouns Made Simple and read Rule 3, “The Thumb Rule.”

5.  Using unnecessary apostrophes with the letter “s.”
Here’s a quick lesson: Use apostrophes only in contractions (don’t, can’t) and “of” ideas (Mary’s car, Tom’s schedule).
Apostrophes aren’t decorations, and they don’t mean more than one!

The cars will be replaced in two years. (no “of” ideas, and no apostrophes)  CORRECT
John’s laptop isn’t working properly. (laptop of John)  CORRECT
The Browns are taking a vacation next month. (no “of” ideas, and no apostrophes)
My uniform doesn’t need to be dry cleaned until next week. (don’t is a contraction)  CORRECT

For more help with apostrophes, go to About Apostrophes.
Need more help? Check out the resources at


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