Another grammar point we talked about over a year ago is the difference between you’re and your. Do you remember? Take the test (link to: grammar.cl) and see whether you’ve understood the rules. But don’t worry if you don’t. You can always take a look at them here.
“Your” shows possession. Try replacing “your” with “my” in a sentence. If it works, then use “your”.
Example: “Is this your office?” (This means: Does this office belong to you?)
“You’re” is a contraction or combination of “you are”.
Example: “Please phone me when you’re in Cologne”. (This means: Please phone me when you are in Cologne.)
Don’t worry too much. Even native speakers get this wrong! 😉