There are 3 groups of words that are among the most often confused words in the English language – and so they lead to the most common grammar mistakes.  Beginning English language learners, advanced learners, even native English speakers misuse:

good and well;  its and it’s;  they’re, their, and there 

Knowing more specifically what each word means, and how or when to use it, will help you avoid falling prey to these common grammar mistakes.

Words That Can Easily Lead to Grammar Mistakes

They’re vs Their vs There

These words are confused with one another because they are homophones—they sound alike when spoken—you know what you mean when you say the words but an issue arises when you are writing them in English.

They’re, is a contraction of the words they and are.  They is the subject.  Are is the verb.  As a matter of fact, substituting the words they and are mentally for when you see, read, or are writing this word is the perfect test to see if you are using the contraction, they’re, correctly.

For example:
You wouldn’t say…     It’s over they are.
But you would say…         They are having fun.

Their is a possessive pronoun.  Their is used when something, even an attribute or condition, belongs to them so it is usually followed by a noun.

For example:
I have their books.
Their family is large.
Where is their integrity?
Their laugh is infectious.

The word there indicates a place and is the opposite of here.

For example:
He’s over there.
Your glasses are there, on the table.

The phrases: there is / there are, are common introductory phrases often used in descriptive sentences.

For example:
There are leaves all over the yard.
There is a problem with that sentence.

Good vs Well

Good is an adjective—a word that modifies a noun or pronoun.  Adjectives like, good describe nouns or pronouns.

For example:
The food was so good!
Her English is good.

Well is an adverb—a word that modifies a verb, adjective, or another adverb.  Fun fact, well is the adverb equivalent of good!  Adverbs like, well, are used to answer “how” questions.

For example:
He’s feeling well.
She did really well on her English exam.

It’s vs Its

Normally possessives have an apostrophe before the “s”—not the case with the word, its.  Its, is like the possessive pronouns, his and her, it shows possession without an apostrophe “s”.  If you’re confused on whether to use the word its without an apostrophe sometimes (but not always) mentally replacing it with the word his or her can clarify the issue.

For example:
The bird broke its wing.
The dog buried its bone in the backyard.
This game has its own set of rules.

It’s, is a contraction of the words it and is or it and has.  The trick here is to try replacing the word with “it is” or “it has” to see if you’re using the proper form.

For example:
Whenever it’s a holiday, traffic doubles.
It’s been years since I was out ‘til dawn.

The 3 grammar mistakes above can easily trip up ESL students and native English speakers equally.  Pay attention to the specifics of the individual word’s usage, and try the tips I’ve mentioned.  The correct grammar usage will become second nature in no time.