There is a difference between “your” and “you’re.” There is also a difference between “there,” “their,” and “they’re.” These are language skills you learned in elementary school and I PERSONALLY know two dozen African children with less education than you who manage to use these words correctly.
If you are an adult and you write sentences like “It sucks when your on a computer and someone else is signed into there Facebook,” then you should be struck by lightning and all your worldly goods should go to a disadvantaged child who knows better.
Things That Exist 