English can be a complicated and confusing language. You could be having a simple conversation with a friend, and suddenly, you may be confused about whether to use “who” or “whom” in a sentence. Or maybe you’re unsure if it’s “affect” or “effect.” If so, you are not alone! In fact, there are several common grammar mistakes that even the most well-read students can make.

In this article, we will go over the ten most common English grammar mistakes and give you tips on how to avoid them. Whether you’re writing an essay for school or just want to improve your grammar skills, this post can help you with the English grammar basics.

10 Most Common Grammar Mistakes

1. Then and Than

Then and than may sound similar but mean very different things.

  • Then is typically used to describe something in relation to time.
    • Example: I will go for a walk, then I will water my plants.
  • Than is used when comparing two things.
    • Example: She runs faster than her.
Tip to Remember

To know if you are using the word correctly, try using your sentence by replacing the word with “when”. Both “when’ and “then” are associated with time and are also related words. If the question makes sense, then you should use “then” in the sentence. For example: When did you do it? I did it then.

2. Lie and Lay

Lie and lay are words that are commonly used interchangeably. Although meaning something similar, lie and lay are used to refer to different things.

  • Lie is a verb that means “to recline or be in a horizontal position,” like when someone needs to lie down.
    • Example: You seem tired, do you want to lie down?
  • Lay is to place or put something down. It is usually used to refer to an object.
    • Example: You can lay the carpet over there.

Tip to Remember

Lie has the word “I” in it and is used to refer to oneself or another person being in a horizontal position. Whereas lay is an action word used to refer to a direct object.

3. Who and Whom

This is another pairing of words that can be hard to differentiate. “Whom” is typically not used in casual conversations. Although, if you want to pursue a career in academics, writing, or anything that revolves heavily around the English language, it is better to understand the difference between the two.

  • Who is used as a subject in a sentence. It is used when the word is performing the action.
    • Example: Who wants to go out for dinner?
  • Whom is used as an object in a sentence. It is used when it is receiving the action.
    • Example: The letter was addressed to whom?

Tips to Remember

If you can replace the word in your sentence with “he,” “she,” or “they” (subject), then “who” is the correct word to be used. If you can replace it with “him,” “her,” or “them” (object), then “whom” is the correct word.

4. Affect and Effect

  • Affect is used as a verb. It means “to act on something.”
    • Example: The power outage affected our entire neighborhood.
  • Effect is used as a noun and is usually used to show the end result of something; after something is done.
    • Example: What effect will the medicine have on my body?

Tips to Remember

Remember that “Affect” = action. “Effect” = end result.

Similar sounding words

The English language has many words that sound similar or are spelled similarly but have different meanings. These words not only confuse but can make it hard for non-native speakers to learn the language and become fluent.

Here are some examples of similar-sounding words, or homophones, that can confuse people with some tips to differentiate:

5. There, Their, and They’re

These three words sound the same but are spelled differently and have different meanings and purposes in English.

  • There is usually used as a noun or adjective. It refers to a place or expresses where an action is taking place.
    • Example: There is my pen.
  • Their is the possessive pronoun of “they”. It usually means “belonging to”.
    • Example: It is their newspaper.
  • They’re is a contraction of they are.
    • Example: They’re not a very friendly bunch. / They are not a very friendly bunch.

Tips to Remember

If you cannot understand which word is appropriate in a sentence, try replacing it with “here”. Here, with a T, in the beginning, is there – both referring to a place. If the sentence makes sense, you can use “there”.

“Their” is always used to describe the ownership of something in relation to someone. It also has the word “heir” in it, which means possession or ownership.

To remember how to correctly use “they’re,” simply break down the word into “they are.”

6. You’re and Your

You’re and your are another example of homophones.

  • You’re is a contraction of you are.
    • Example: You’re learning how to ride a bike / You are learning how to ride a bike.
  • Your is a possessive adjective. It is used to describe something that belongs to you.
    • Example: Can I borrow your Math notes?

Tip to Remember

When trying to use it in a sentence, always break it down into “you are”. If the sentence sounds correct, then you should use “you’re”. If the sentence does not make sense, then you should use “your”.

7. To, Too, and Two

Now this might seem like an easy set of homophones, but to, too, and two can be easily confused simply because they sound similar.

  • To is a preposition. It is used to express direction or motion towards something.
    • Example: I went to the store.
  • Too is an adverb and usually means “also” or “additionally.”
    • Example: Would you like to have ice cream too?
  • Two is the written form of the number 2.
    • Example: She has two pens.

Tips to Remember

If you are confused between “to” and “too”, try substituting the word with “also”. Both “too” and “also” mean additionally. If the sentence makes sense after you replace it with “also”, then you should use “too”.

Another way to differentiate between “to” and “too” is to remove it from the sentence. If you remove “to” from a sentence, it would not make sense, but if you remove “too” from the sentence, it will not affect what the sentence is trying to convey.

For example: Would you like to have ice cream too?

  • If you remove “to,” you get: Would you like have ice cream too?
  • If you remove “too,” you get: Would you like to have ice cream?

8. Principal and Principle

  • Principal is the head of a school or organization. This word is used to describe a person. If used as an adjective, it can also mean “main” or “primary.”
    • Example: Have you met my school principal?
  • Principle is a rule, truth, or theory. It is always used as a noun to describe an abstract thing.
    • Example: Isaac Newton uncovered the principles of gravity and motion.

Tips to Remember

The word “principal” has the word “pal” in it. If you want to talk about the head of an organization or a person who is the main authority, remember to use “principal” with the word “pal” in it.

9. Weather and Whether

  • Whether is a conjunction and is used to introduce a choice or doubt between two alternatives.
    • Example: She could not decide whether to buy a new bag or use her old one.
  • Weather is primarily used as a noun to describe the atmospheric condition of a place.
    • Example: We are expecting some bad weather tomorrow.

Tip to Remember

A good way to remember the difference between the two is to notice that “whether” has two “h” in it and is used to introduce a choice between two or more things.

10. It’s and Its

  • It’s is the contraction of “it is” or “it has”.
    • Example: It’s a good day to go out for a picnic.
  • Its is a possessive form of the word “it”. It is used to indicate possession or ownership.
    • Example: The restaurant has increased its rates.

Tip to Remember

If you get confused between it’s or its, replace the word with “it is” or “it has”. If the sentence makes sense with either of those substitutions, use “it’s”. If the resulting sentence doesn’t make sense, you need “its”.

Even well-read individuals can make common mistakes, but by using the tips we’ve discussed, you can enhance your written and spoken English, whether for academic purposes or personal growth.

Can you think of any more common grammar mistakes? Let us know and we can help you remember how to use them correctly!­

Need Grammar Tutoring?

Our amazing tutors can help your student with the confusing rules of grammar or the basics of writing.