1. Using of instead of have.
Wrong: You should of known.
Right: You should have known.
Also Right: You should’ve known.
This is what happens when people spell what they hear. The proper spelling of “should/could/would of” is should’ve (should have), could’ve (could have), and would’ve (would have). The have (‘ve) in should’ve is pronounced like of, leading to the misconception.
2. Confusing whose with who’s.
Wrong: Who’s shoes are those?
Right: Whose shoes are those?
Who’s is short for who is. It doesn’t make sense to say “who is shoes are those” does it? Whose is the possessive case of who, meaning that if we are referring to someone else’s belongings, we use whose. Always ask yourself, does who is make sense in this sentence? If it doesn’t, use whose.
3. Dropping the oxford comma.
Wrong: I like reading about North American hamsters, Madonna and Tupac.
Right: I like reading about North American hamsters, Madonna, and Tupac.
A comma after Madonna makes the distinction that you like reading about three different subjects. Without the comma, you’d be saying that you like reading about two hamsters named Madonna and Tupac.
4. Confusing affect and effect.
Wrong: How did the accident effect you?
Right: How did the accident affect you?
A simple way to remember the difference between affect and effect: affect is a verb and effect is a noun.
5. Believing that you can’t start a sentence with because.
Wrong: I don’t like going to the seafood aisle. Because it stinks.
Right: Because it stinks, I don’t like going to the seafood aisle.
Also Right: I don’t like going to the seafood aisle because it stinks.
I had a teacher who would preach to my 5th grade class that we couldn’t begin sentences with the word because. I didn’t listen her since I had seen many sentences written starting with the word in books that I’d read. She never took any points off of my assignments for ignoring her rule, which begs the question, why was it ever taught? It isn’t true!