You're = not a possessive
Your = possessive
There = not a possessive
Their = possessive
Now let's use these words in a sentence:
Your dog is as ugly as you are.
You're a dumbass who needs to go back to grade two.
There are smarter people in this world than you; 6,999,999,999 of them, in fact.
Their (well your) intelligence is lacking.
And while you're fucking at it, learn the difference between too, two and to.---Smarter Than You