10 Common Grammar Mistakes You May Be Making and How to Avoid Them

By Nadia Vasquez

In a career where strong writing is an essential skill, having strong grammar should be like second nature. While many of us are already equipped with these skills, you may find yourself writing sometimes and thinking, “Is it who or whom?” Or “What is the difference between a lot of words that are spelled quite similar?” This blog post is here to help you. Whether you mix up terms all the time or just need a refresher, these are 10 common mistakes you could be making in your writing and how to avoid.

1. Who vs. Whom
This is one that is very easy to mix up and many probably aren’t even aware of what their difference is. “Who” is used when referring to the subject of a sentence while whom is used as an object of a verb or a preposition. 

Ex: Who asked the question? He asked the question. 
Ex: Whom should I take to the movies? 

The easiest way to differentiate them is by placing pronouns in place. If “he” fits in the sentence, it’s “who”, if “him” fits, it’s “whom”. 

2. Lie vs. Lay
This is another pair of words that are used interchangeably, but there is a difference between them. They are both verbs, but their difference is in their tense. “Lay” is used when you place something down; “lie” is used when the action has been done and it is in the current position of being placed down. 

Ex: I lay down on my bed every night. 
Ex: I lie in bed until noon. 

3. Fewer vs. Less
These words are some you may not recognize you are confusing, but their difference is rather simple. “Fewer” is used for things that can be counted, while “less” is used for things that cannot be counted. 

Ex: There are fewer than three slices of bread left. 
Ex: There is even less water in here than yesterday. 

4. Then vs. Than
These words are probably some of the worst offenders of people’s grammar mistakes. They are very common in today’s time and understanding their difference is important. “Then” is used to show a place in time, while “than” is used when comparing two subjects. 

Ex: She went to the movies, then she went to dinner. 
Ex: She would rather go to the movies than dinner. 

5. To vs. Too
Yet another fairly mixed-up set of words. “To” has several meanings, but most commonly it is used in front of a noun or verb that suggest going to something. Too is used to suggest a large amount or as a synonym for “also.”  

Ex: He is going to the store to buy food. 
Ex: He’s eating way too much food. 

6.  Affect vs. Effect
This is a tough one. Many people aren’t aware of the difference between these two words and have probably been too scared to ask. Their difference is actually quite simple. “Affect” is used as a verb and shows action, while “effect” is a noun that is the result of a change. 

Ex: She didn’t know the sun would affect her car. 
Ex: The sun had a harsh effect on her car. 

7. Your vs. You’re
These two are constantly used interchangeably despite their simple differences. “Your” is a possessive adjective that is used to describe something belonging to you, while “you’re” is a contraction of the words “you are.” A good trick to remember is if you can replace “you’re/your” in the sentence with “you are,” then the proper choice for that sentence is “you’re.”

Ex: Your car is dirty; you should wash it. 
Ex: You’re very optimistic today. 

8. Peek vs. Peak
Are you looking at something or are you cresting something?  Peak is used when discussing the top or point of something, while peek is used when referring to looking. 

Ex: They’re at the peak of the mountain. 
Ex: They’re taking a peek at tomorrow’s work. 

9. Loose vs Lose
These are mixed up easily because of their close spelling. However, they have very big differences. “Loose” is used to show that something is not tight or contained, while “lose” is used as a verb to show loss of something. 

Ex: Everything is falling out because the pockets are loose.
Ex: It’s a shame they had to lose their spot. 

10. Ensure vs Assure
While these words may not seem like they will be mixed up, it is still easy to misuse them. 
“Ensure” is used when making something certain and “assure” is used to remove doubt and place confidence. Even their explanations sound quite similar.

Ex: I assure you this mistake won’t happen again. 
Ex: I will ensure that he makes it to his appointment. 
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The English language can be confusing with many similar words. But by remembering these 10 commonly misused words, you can improve your writing and your grades.