1. Your and You're
YOU'RE --> Means YOU ARE
EXAMPLES : You're my friend --> you are my friend
You're so smart --> you are so smart
WRONG WAY TO USE YOU'RE --->
Is this you're book? Wrong!!
You're dog is so playful! Wrong!!
How do i know its wrong? Well...look at it this way....like i said you're means YOU ARE.
The 'a' in 'are' is replaced by an apostrophe ( ' ) and joined to 'you' resulting in the word --> YOU'RE
So the two sentences above actually mean
Is this you are book?
You are dog is so playful!
See? WRONG! In such cases you use the word YOUR
So the right way to say this is : is this your book?
Your dog is so playful!
Never confuse yourself with You're and Your.
I hope this has cleared your confusion :)