Common Grammatical Errors

Note: These rules are only a guide. The English language is filled with exceptions and contradictions.

1. Your vs You're
Your: To show possession. Eg. "I love your new car."
You're: A contraction of 'you are'. Eg. "Tomorrow, you're going to paint the walls."

2. Its vs It's
Its: To show possession. Eg. "What’s that? I can’t remember its name."
It's: A contraction of 'it is'. Eg. "It’s going to be sunny tomorrow."

3. There vs Their vs They're
There: Refers to a location or place. Eg. "I am going to the beach. It will be very sunny there."
Their: Refers to something that is in the possession of more than one person. Eg. "The kids were down by the lake trying to get their ball."
They're: A contraction of 'they are'. Eg. "Next week, they're giving a presentation."

4. Affect vs Effect
Affect: Verb. “Affect” means to influence or produce an impression — to cause hence, an effect.
Effect: Noun. “Effect” is the thing produced by the affecting agent; it describes the result or outcome.
For example, "A person's actions can affect the end effect."

5. Then vs Than
Then: Has a variety of meanings, including 'at this point in time' or 'in addition to'.
Than: When comparing objects. Eg. "The orange is bigger than the apple."
Use 'than' when comparing and 'then' in all other instances.

6. Loose vs Lose
Loose: Overly big, free.
Lose: Opposite of win, misplace.
For example, "If your pants are too loose, you might lose your them."

7. Me, Myself and I
(direct quote, source 2)
One of the most common causes of grammatical pain is the choice between “me” and “I.” Too often people use “I” when they should use “me,” because since “I” sounds stilted and proper, it must be right, right? Nope.

The easy way to get this one right is to simply remove the other person from the sentence and then do what sounds correct. You would never say “Give I a call,” so you also wouldn’t say “Give Chris and I a call.” Don’t be afraid of me.

And whatever you do, don’t punt and say “myself” because you’re not sure whether “me” or “I” is the correct choice. “Myself” is only proper in two contexts, both of which are demonstrated below.

"Many consider Chris a punk, but I myself tolerate him. Which brings me to ask myself, why?"

8. Improper use of apostrophe
There are only two reasons to use an apostrophe:
1. For contractions. Eg. 'don't' for 'do not'.
2. To show possession. Eg. 'Jim's desk' means the desk belongs to Jim.
If in doubt, leave it out. A misplaced apostrophe causes more confusion than an omitted one.

9. Could of, would of, should of
Incorrect: "I should of gone to the baseball game, and I could of, if Billy would of done his job."
Correct: "I should have gone to the baseball game, and could have, if Billy had done his job."

(direct quote, source 2)
Why do people make this mistake?
They could’ve, should’ve, would’ve been correct, except that the ending of those contractions is slurred when spoken. This creates something similar to a homophone, i.e., a word that is pronounced the same as another word but differs in meaning, e.g., of, which results in the common grammatical mistake of substituting of for have.

10. Principal vs Principle
Principal: Usually refers to the head of a school. Can mean highest in rank or the main participant. As an adjective, it means the most important of a set.
Principle: Noun. Means a fundamental truth, law or standard.

11. Literally
Literally: Exactly what you say is true.
Correct: "I literally searched every room in the house."
Incorrect: "I am literally dying of boredom."

12. The dangling participle
(direct quote, source 1)
A dangling participle occurs when you order a sentence in a confusing way. For example, "After rotting in the cellar for weeks, my brother brought up some oranges." This means your brother has turned into a zombie who delivers fruit. Try instead, "My brother brought up some oranges that had been rotting in the cellar for weeks."

13. Irony vs Coincidence
(direct quote, source 3)
Too many people claim something is the former when they actually mean the latter. For example, it’s not “ironic” that “Barbara moved from California to New York, where she ended up meeting and falling in love with a fellow Californian.” The fact that they’re both from California is a "coincidence." "Irony" is the incongruity in a series of events between the expected results and the actual results. "Coincidence" is a series of events that appear planned when they’re actually accidental. So, it would be "ironic" if “Barbara moved from California to New York to escape California men, but the first man she ended up meeting and falling in love with was a fellow Californian.”

14. Since vs Because
Since: Refers to time. Eg. "Since I quit drinking, I’ve married and had two children."
Because: Refers to cause and effect. Eg. "Because I quit drinking I no longer wake up in my own vomit."

Sources:
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