Common Grammar Mistakes You May Be Making

It’s no secret that English is a tough and pretty weird language to learn. There are so many grammar rules and exceptions that even the best of us make mistakes every now and then. However, some grammar mistakes are more common than others. In fact, you might be making some simple grammar mistakes without even knowing it. To do our part in helping everybody become a grammar great, we’ve put together a list that will help solve some of the most common grammar mistakes out there. Keep this list handy before you turn in your next paper or hit send on that important email to be the boss!

Mistake 1: who or whom?

Let’s start with a biggie: who and whom are a pair of commonly confused pronouns that are often used to ask questions or refer to unknown people. In short, who is a subject pronoun while whom is an object pronoun. This means that you would use who as you would use I, he, she, and they, and you would use whom in the same places as me, him, them, and us. For example:

• Who (subject) ate my lunch?
• You went to the beach with whom (object)?

But interrogative sentences often jumble word order around, and many writers hesitate to place the object whom at the beginning of the sentence. Although correct, it just seems odd. For example:

• Whom (object) did you (subject) ask questions to?

All of that said, in informal speech and writing, speakers will often opt for who where whom has traditionally been used. To learn much more about the differences between who and whom, check out our guide When Do You Use “Who” vs. “Whom”?

Mistake 2: who or that?

Who is back again to confuse us. Who and that are another pair of pronouns that can be easily mixed up. Generally speaking, who is used to refer to people (and possibly named animals) and that is used to refer to non-living things (and possibly unnamed animals). For example:

• Who lives here? (refers to a person or people)
• I never want to see that again. (refers to a thing or unnamed animal)

Both who and that can also be used as relative pronouns to introduce relative clauses that describe nouns. As before, who is typically used to refer to people while that is used to refer to objects.

• I sat by the girl (person) who was wearing a hat.
• Kelly bought a car (object) that has good gas mileage.

That being said, that is often used to describe people in informal writing. For example:

• He just met the girl that moved in next door.

Most style guides recommend avoiding using that in this way in formal writing.

Mistake 3: commas—all the commas

We move from the apostrophe to possibly the most dreaded punctuation mark of all: the comma. It is hard to know where to even begin with commas, as they are the source of many, many grammar errors. To really master commas, you are best off checking out our amazing guide to proper comma usage. For now, we’ll just look at a couple of common comma mistakes to avoid:

Common comma mistake: the splice

This mistake occurs when a comma appears where it shouldn’t. When joining two independent clauses, a comma needs to be followed by a conjunction. But using a comma by itself (as in the first sentence below) is considered an error.

❌ Mistake: I like strawberry ice cream, my sister doesn’t.
✅ Fixed: I like strawberry ice cream, but my sister doesn’t.

Common comma mistake: tricky subordinate clauses

Subordinate clauses do not require a comma, and it is considered a mistake to use one.

❌ Mistake: Luke avoids cats, because he is allergic to them.
✅ Fixed: Luke avoids cats because he is allergic to them.

Subordinate clauses begin with subordinating conjunctions, such as because, after, before, since, or although.

Mistake 4: its or it’s?

Only a single apostrophe separates the frustrating duo if its and it’s. The word its is a possessive pronoun that is used like the words my, his, her, and our. The word it’s is a contraction for the phrase “it is” or “it has.” Despite how similar they look, its and it’s have completely different meanings and usage. For example:

• The door fell off its (possessive) hinges.
• The idea is really bad but it’s (“it is”) the only one we have.

This common mistake likely has to do with the fact that an apostrophe is used to form the possessive of nouns such as Dave’s or Canada’s. As weird as it looks, its is in fact a possessive despite not using an apostrophe.

If you are still a little lost, our thorough guide to its and it’s can provide more assistance in separating these two very similar words.

Mistake 5: their, there, and they’re? (And what about your or you’re?)

Their, there, and they’re are a trio of homophones that frequently get mistaken for one another. However, they all have different, unique meanings. Let’s look at each one.

Their is the possessive form of they, and it can be used in place of either the singular or plural they to express ownership or possession. For example:

• The scientists put on their lab coats.

They’re is a contraction of they are and fills in for it to shorten sentences. For example:

• Becky and Jayden were supposed to be here already, but they’re (“they are”) late.

There is a word that usually means “that place” as in Tokyo looks so exciting; I wish I could go there. It has a few other meanings, but it isn’t a synonym of either their or they’re.

Your and you’re are another pair of homophones that commonly get mixed up. Like their, your is the possessive form of the singular and plural you. Like they’re, you’re is a contraction that stands for “you are.” Here are examples of how we use these two similar words:

• I like your jacket. (possession)
• You’re (“you are”) smarter than you think.

For more examples, check out our guides “Their” vs. “There” vs. “They’re”: Do You Know The Difference? and “Your” vs. “You’re”: How To Choose The Right Word.

Mistake 6: me or I?

At first glance, me and I seem simple enough: I is a subject pronoun and me is an object pronoun. We use I as the subject of sentences/clauses and me as the object. For example:

• I (subject) went to sleep.
• Erica likes me (object).

However, it can be easy to forget these rules when sentences get more complicated, and it gets harder to figure out if something is a subject or object.

• Chris, Daniela, and I (compound subject) played soccer.
• Dad sent birthday presents to my sister and me (compound object).

The main source of this confusion might be the word than, which can be used as either a conjunction or a preposition. Because of this, both of the following sentences are correct:

• Nobody sings karaoke better than I.
• Nobody sings karaoke better than me.

If you want to learn more, head on over to our article explaining the differences between me vs I.

Mistake 7: dangling modifiers

When we use modifiers such as adverbial or participial phrases, we typically want to place them as close to the word they modify as possible. Otherwise, a sentence may end up with a type of mistake called a “dangling modifier.” A dangling modifier is a phrase or clause that either appears to modify the wrong things or seems to modify nothing at all. This common grammar mistake can result in confusing or unintentionally funny sentences. To fix these misplaced modifiers, you’ll want to place them close to the word they modify and make it clear which word or part of the sentence they modify. For example:

❌ Mistake: While driving, a bear walked in front of my car. (Is a bear driving something?)
✅ Fixed: While I was driving my car, a bear walked in front of me.

❌ Mistake: Rubbing their hands together, the winter weather was harsh and cold. (Whoever is rubbing their hands is missing.)
✅ Fixed: Rubbing their hands together, the explorers tried to stay warm in the harsh and cold winter weather.

❌ Mistake: Yesterday, I found a stray dog in my underpants. (Was the dog hiding inside your underpants?)
✅ Fixed: While wearing just my underpants, I found a stray dog yesterday.

Mistake 8: pronoun antecedents

When we use pronouns, they must agree in number with their antecedents. The antecedent is the noun that a pronoun is filling in for. It is a mistake to use a plural pronoun with a singular antecedent and a singular pronoun with a plural antecedent. For example:

❌ Mistake: The bees hid in its hive.
✅ Fixed: The bees hid in their hive.

Additionally, we wouldn’t use its to refer to a person, nor would we use personal pronouns to refer to non-living things.

❌ Mistake: The zoo that Amanda owns is having her grand opening tomorrow.
✅ Fixed: The zoo that Amanda owns is having its grand opening tomorrow.

At the same time, it should be clear in a sentence what a pronoun’s antecedent actually is. Avoid making the mistake of having missing or unclear antecedents.

Missing antecedent: I looked everywhere but couldn’t find her. (Who is her?)
Unclear antecedent: The toaster was next to the sink when it broke. (What broke? Does “it” refer to the toaster or the sink?)

To learn a lot more about pronouns and how to use them, check out our great guide to pronouns here.

Mistake 9: semicolons

For many, the semicolon is not a punctuation mark that sees a lot of use, which may explain why people make mistakes when trying to use it. As it turns out, semicolons are fairly simple to use. The main thing to remember when using a semicolon is that the independent clause following the semicolon doesn’t begin with a capital letter unless it begins with a proper noun. For example:

• I love cats; they are cute and smart.
• Jack and Jill went up a hill; Jill made it up first.

Remembering this simple rule will go a long way toward ensuring proper semicolon usage. If you want to learn everything else there is to know about semicolons, we have a comprehensive guide to them, What Are Semicolons (;) And How Do You Use Them?