20 Of The Most Common Grammatical Errors We All Need To Stop Making

It’s not easy. Words and phrases that sound fine in your head can look like gibberish when written down — that is, if you even realize you made a mistake in the first place. It’s easy for little grammar mistakes to slip by, especially when you’re self-editing.
But how do you prevent grammatical errors if you’re not even aware you’re making them?

Well, you can start by reading through this post to see which common grammar mistakes resonate with you the most. (It’s okay — we’re all guilty of at least one.) Make a mental note to avoid that mistake in the future, or heck, just bookmark this page to remind yourself of them over and over (and over) again.

20 Common Grammar Mistakes to Check For in Your Writing
1) They’re vs. Their vs. There
One’s a contraction for “they are” (they’re), one refers to something owned by a group (their), and one refers to a place (there). You know the difference among the three — just make sure you triple check that you’re using the right ones in the right places at the right times.
Correct Usage: They’re going to love going there — I heard their food is the best!

2) Your vs. You’re
The difference between these two is owning something versus actually being something:

You made it around the track in under a minute — you’re fast!

How’s your fast going? Are you hungry?

See the difference? “Your” is possessive and “you’re” is a contraction of “you are.” Again, if you’re having trouble keeping them straight, try doing another grammar check before you hit publish.

3) Its vs. It’s
This one tends to confuse even the best of writers. “Its” is possessive and “it’s” is a contraction of “it is.” Lots of people get tripped up because “it’s” has an ‘s after it, which normally means something is possessive. But in this case, it’s actually a contraction.

Do a control + F to find this mistake in your writing. It’s really hard to catch on your own, but it’s a mistake everyone can make.

4) Incomplete Comparisons
This one drives me up a wall when I see it in the wild. Can you see what’s wrong with this sentence?

Our car model is faster, better, stronger.

Faster, better, stronger … than what? What are you comparing your car to? A horse? A competitor’s car? An older model?

When you’re asserting that something should be compared to something else, make sure you always clarify what that something else is. Otherwise, it’s impossible for your readers to discern what the comparison actually means.

5) Referring to a Brand or an Entity as “They”
A business ethics professor made me aware of this mistake. “A business is not plural,” he told our class. “Therefore, the business is not ‘they.’ It’s ‘it.’”

So, what’s the problem with this sentence?

To keep up with their changing audience, Southwest Airlines rebranded in 2014.

The confusion is understandable. In English, we don’t identify a brand or an entity as “he” or “she” — so “they” seems to make more sense. But as the professor pointed out, it’s just not accurate. A brand or an entity is “it.”

To keep up with its changing audience, Southwest Airlines rebranded in 2014.

It might seem a little strange at first, but once you start correctly referring to a brand or entity as “it,” the phrasing will sound much more natural than “they.”

6) Possessive Nouns
Most possessive nouns will have an apostrophe — but where you put that apostrophe can be confusing. Here are a few general rules to follow:

If the noun is plural, add the apostrophe after the s. For example: the dogs’ bones.
If the noun is singular and ends in s, you should also put the apostrophe after the s. For example: the dress’ blue color.
On the other hand, if the noun is singular and doesn’t end in an s, you’ll add the apostrophe before the s. For example: the lizard’s tail.
Simple, right? If you want a deeper dive into the rules of possessive nouns, check out this website.

7) Affect vs. Effect
This one is another one of my pet peeves. Most people confuse them when they’re talking about something changing another thing.

When you’re talking about the change itself — the noun — you’ll use “effect.”

That movie had a great effect on me.

When you’re talking about the act of changing — the verb — you’ll use “affect.”

That movie affected me greatly.

 Me vs. I
Most people understand the difference between the two of these, until it comes time for them to use one in a sentence. They’ll say something like:

When you get done with that lab report, can you send it to Bill and I?

But that’s wrong.

Try taking Bill out of that sentence — it sounds weird, right? You would never ask someone to send something to “I” when he or she is done. The reason it sounds weird is because “I” is the object of that sentence — and “I” should not be used in objects. In that situation, you’d use “me.”

When you get done with that lab report, can you send it to Bill and me?

Much better.

9) To vs. Too
We’ve all accidentally left the second “o” off of “too” when texting in a hurry. But in case the mistake goes beyond that, let’s review some usage rules.

“To” is typically used before a noun or verb, and describes a destination, recipient, or action. Take these examples:

My friend drove me to my doctor’s appointment. (Destination)

I sent the files to my boss. (Recipient)

I’m going to get a cup of coffee. (Action)

“Too,” on the other hand, is a word that’s used as an alternative to “also” or “as well.” It’s also used to describe an adjective in extremes. Have a look:

My colleague, Sophia Bernazzani, writes for the HubSpot marketing blog, too.

She, too, is vegan.

We both think it’s too cold outside.

You might have noticed that there’s some interesting comma usage where the word “too” is involved. We’ll cover commas a bit more later, but when you’re using the word “too” to replace “also” or “as well,” the general rule is to use a comma both before and after. The only exception occurs when “too” is the last word in the sentence — then, follow it with a period.

10) Do’s and Don’ts
I’m not talking about the do’s and don’ts of grammar here — I’m talking about the actual words: “do’s” and “don’ts.” They look weird, right? That’s because of two things:

There’s an apostrophe in one to make it plural … which typically isn’t done, and
The apostrophes aren’t put in the same place in both words.
Unfortunately, it’s AP Style, so we just have to live with it. It’s a hot angle for content formats, so I wouldn’t shy away from using it. But when you’re checking your writing for grammatical errors, just remember that the apostrophes should be in different places.

Note: There are different schools of thought about how to punctuate this one depending on what style guide/usage book you’re using. The Chicago Manual of Style, for instance, recommends “dos” and “don’ts.” The important thing is to be consistent and stick to one style guide, whether it’s AP Style, Chicago, or your own house style guide.

11) i.e. vs. e.g.
Confession: I never remember this rule, so I have to Google it every single time I want to use it in my writing. I’m hoping that by writing about it here, the trend will stop.

Many people use the terms interchangeably when trying to elaborate on a point, but each one means something different: “i.e.” roughly means “that is” or “in other words,” while “e.g.” means “example given” or “for example.” The former is used to clarify something you’ve said, while the latter adds color to a story through an example.

12) Peek vs. Peak vs. Pique
This mistake is another one I often see people make, even if they know what they mean.

Peek is taking a quick look at something — like a sneak peek of a new film.
Peak is a sharp point — like the peak of a mountain.
And pique means to provoke or instigate — you know, like your interest.
If you’re going to use one in your writing, stop and think for a second — is that the right “peek” you should be using?

13) Who vs. That
This one is tricky. These two words can be used when you’re describing someone or something through a phrase like, “Lindsay is a blogger who likes ice cream.” When you’re describing a person, be sure to use “who.”

When you’re describing an object, use “that.” For example, you should say, “Her computer is the one that overheats all the time.” It’s pretty simple, but definitely something that gets overlooked frequently.

14) Who vs. Whom vs. Whose vs. Who’s
Whoa. This one looks like a bit of a doozy. Let’s break it down, shall we?

“Who” is used to identify a living pronoun. If you asked, “Who ate all of the cookies?” the answer could be a person, like myself (“I did”), or another living being (“the dog did”).

Hey, both are realistic scenarios in my world.

“Whom” is a little trickier. It’s usually used to describe someone who’s receiving something, like a letter — “To whom will it be addressed?” But it can also be used to describe someone on the receiving end of an action, like in this sentence:

Whom did we hire to join the podcast team?

“Whose” is used to assign ownership to someone. See if you can spot the error in this question:

Who’s sweater is that?

Because the sweater belongs to someone, it should actually be written this way:

Whose sweater is that?

“Who’s,” on the other hand, is used to identify a living being. It’s a contraction for “who is” — here’s an example of how we might use it in a sentence here in Boston:

Who’s pitching for the Red Sox tonight?

See the difference? “Whose” is used to figure out who something belongs to, whereas “who’s” is used to identify someone who’s doing something.