Some of the most commonly observed grammar mistakes people make, along with an explanation about the mistake, and examples of the correct usage.

If there’s one thing I know about the Internet, it’s this: It does not forgive grammatical errors. It’s one thing to text your friend, “wut r u doing tom nite?” (I sincerely hope you don’t do that though.) And quite another to post something even remotely similar online — if you dare, grammar Nazis will pounce on you faster than you can say, “Huh?”

This is not to say that you should work on your grammar just to avoid being trolled online, far from it — a good grasp and efficient use of the language gives you an edge both in your work setting and your interpersonal communication.

Here’s a list of some of the most commonly observed grammar mistakes people make, along with an explanation about the mistake, and examples of the correct usage.

Don’t be offended if this list seems too basic for you (you would be surprised how common these mistakes are). If that’s the case, you should jump straight to the “further resources” section at the end.

1. Its vs. It’s

A really common mistake for something that couldn’t have been any simpler. “Its” is a possessive and “it’s” is a contraction of “it is”.

Maybe one reason why so many get it mixed up is because ‘s is typically used to denote possession — not so in this case.

It’s (it is) a sunny day.
The medicine is well past its expiry date.

2. A vs. An

This one gets a bit tricky. Most of us learned to put a before words that start with consonants (all non-vowels) and an before words that start with vowels, but that doesn’t always work. If it did, we should be calling it “a hour” instead of “an hour”.

Instead of consonants and vowels, this grammar rule has more to do with consonant and vowel sounds. Use a before words that start with a consonant sound and an before words that start with a vowel sound.

Would you be interested in going for a history tour of the city? (consonant sound)
He is an honorable person. (vowel sound)

Notice that both words, i.e., history and honorable, start with a consonant but only one has a consonant sound while the other has a vowel (o) sound.

3. Your vs. You’re

You may have noticed the pattern by now, “your” indicates possession whereas “you’re” is simply a contraction for “you are”.

You left your jacket at my house last night.
Let me tell you something — you’re absolutely crazy.

4. Whose vs Who’s

Another one from the same family of errors but a surprisingly common one nevertheless, “whose” indicated possession whereas “who’s” is a contraction of “who is”.

Whose side are you on anyway?
Who’s (who is) that guy over there by the bar?

By the way, if, for whatever reason, you tend to mix up your possessions with your contractions… a good way to get into the habit of using them correctly is just to not use contractions for a while.

Instead of “it’s”, “you’re”, and “they’re”, just write it is, you are, and they are.

Depending on the phrasing, it may sound awkward in some places but at least you won’t be making a grammatical error. Once you’re more comfortable telling them apart, you can always ease into using the contractions.

5. Their vs. They’re vs. There

“Their” is used to refer to something owned by a group, “they’re” is a contraction of “they are”, and “there” refers to a place.

Their defence is strong.
They’re (they are) a great couple.
I’ll see you there.

6. Loose vs. Lose

Fortunately not as common a mistake as some of the others on the list, but when it does happen, it makes you cringe like nothing else. It obviously happens because they have a very similar spelling, but that’s where the similarity ends.

“Loose” is an adjective that means not firmly or tightly fixed in place; detached or able to be detached.

“Lose” is a verb that means to be deprived of or cease to have or retain (something).

So, you lose your keys, you don’t loose them. And those pants are not lose, no sir.

7. Less vs. Fewer

Some may call it nitpicking, but the devil is in the details. Ever seen a sign in the express checkout lane that reads, “5 items or less.”? Well, it’s incorrect. It should be fewer.

Here’s the distinction: You use “fewer” for things that are quantifiable and “less” for things that cannot be quantified. Here are a few examples from Quick And Dirty Tips:

You can count M&Ms, glasses of water, and potatoes—so you eat fewer M&Ms, serve fewer glasses of water, and buy fewer potatoes for the salad.

You can’t count candy, water, or potato salad—so you eat less candy, observe that the lake has less water, and make less potato salad for the next potluck.

8. Than vs. Then

Often mistaken for each other because they sound almost the same and are spelt almost the same, but, you guessed it, have literally nothing else in common.

“Than” is a conjuction that is used mostly for making comparisons. The most common use of “then” is as an adverb where it helps defines the flow of actions in time.

I am smarter than you.
Come over to my place, then we’ll decide where to go next.

9. Passive voice

Okay, let’s be clear on this, passive voice is not really a mistake per se, but it is more difficult to process mentally than active voice — so you’re not doing your readers a favor when you use the former.

But wait, what is active voice and passive voice anyway? Good question.

When the subject in a phrase precedes the object, it’s active voice.

I sent the email.

Here, “I” is the subject and “email” is the object. Now let’s reverse it.

The email was sent by me.

This is now passive voice because the object now precedes the subject.

Yes, it can be a bit tricky to get at first, for a more detailed explanation, head over to this post on active and passive voice.

Again, just to emphasize, using a passive voice isn’t a mistake, but your readers will love you for sticking with active.

10. Possessive nouns

It’s easy to get your apostrophe mixed up when using possessive nouns because there are very subtle differences between usage, but if you mix them up, it looks ignorant.

Let’s break it down to three simple rules:

If the noun is plural, put the apostrophe after the s.

The birds’ feeding pattern is a bit strange.

If the noun is singular but ends with an s, put the apostrophe after the s.

The dress’ color was black and blue.

If the noun is singular and does not end with an s, put the apostrophe before the s.

I really like Karen’s sense of style.

Further resources


I’d like to just say that this is anything but a conclusive list of grammatical errors — instead, this is a list of the most common ones that I happen to come across. There are in fact so many more that it’s not practical to list them all down in one post.

In my opinion, the best way to avoid making such errors is to choose a source you trust and keep yourself updated since language is always evolving.


1. What are grammatical errors?

The term “grammatical error” refers to parts of a text that do not follow standard grammar rules. These include errors involving parts of speech, word order, subject/verb agreement, and verb tense consistency.

2. Is it grammar or grammatical errors?

Grammar errors and grammatical errors refer to the same problem — errors in standard grammar usage. The difference between the two terms is that ‘grammar error’ is a compound noun, while ‘grammar error’ is a noun modified by an adjective.

3. What is Passive voice?

Passive voice is used when the subject undergoes the action of a verb in one of its forms or sets of forms.


Shubham is a digital marketer with rich experience working in the advertisement technology industry. He has vast experience in the programmatic industry, driving business strategy and scaling functions including but not limited to growth and marketing, Operations, process optimization, and Sales.

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