Along with effect/affect, which we already defined in a previous post, these are some of the words most commonly messed up by native English speakers. Thanks so much to an ESL teacher who submitted them for the Glossary of Confusing Words, saying:
As a former ESL teacher, I frequently had to explain these words to my students. Non-native speakers can be forgiven for finding them confusing, but too many Americans use "it's" as a possessive adjective because it has an apostrophe.
In the word "you’re," the apostrophe indicates a contraction of the words “you” and “are.”
An apostrophe is often used to indicate a contraction, like in "can't" (cannot) or "he'll" (he will). Although contractions are used slightly less in written English than in spoken English, since they're considered less formal, they're still extremely common in the written word.
You’re = You are
“You’re going too fast.”
“You’re so pretty.”
“Your” indicates possession. Just like “my” means that something belongs to me, and “his” means that something belongs to him, “your” means that something belongs to you.
Your = Belongs to you
“Is that your bag?”
“Your house is nice.”
In most of the English language, an apostrophe followed by an “s” can indicate possession - “Look at the bird’s nest,” “The building’s wall was damaged,” “Don’t touch Jessica’s bike!” - or a contraction formed with the word “is”or "has" – “That’s my house,” “He’s gone home,” “What’s up?”
But its/it's is different. The "-'s" is ONLY used to indicate a contraction of "it" and "is" or "has." The possessive form has no apostrophe.
Its = Belongs to it
It’s = It is, it has
If you want to know why this is the case, it's (it is) because possessive adjectives like "its" don't use an apostrophe to indicate possession. Most of the time you follow this rule without thinking about it - you'd never think to write "his" as "hi's," or "my" as "my's." Well, "its" follows this same pattern.
Here are some side-by-side examples:
"It's a gorgeous dog."
"Look at its soft fur!"
"His eyes are so beautiful."
“The building’s wall was damaged.”
“Can its structure be salvaged?”
“I don’t know. It’s pretty bad.”
The full list of possessive adjectives, by the way, is as follows:
Belongs to me = My
Belongs to you = Your
Belongs to him/her = His/Her
Belongs to it = Its
Belongs to us = Our
Belongs to them = Their
Which leads nicely into our final set of commonly mistaken words…
As we just discussed, “their” is a possessive adjective.
“That couch belongs to them. It is their couch.”
Just like with “you’re,” “they’re” is a contraction of “they” and “are.”
“They’re such good friends.”
“They’re living together.”
Finally, “there” is used to indicate a location. It can also indicate the existence or nonexistence of something.
“The subway is over there.”
“There are no cars on the road.”