Level A1
Your vs You're
Your and you're sound the same. Your means it belongs to you (Is this your bag?); you're is short for you are (You're late). If you can say you are, write you're: You're welcome!
You're welcome!
Look: You're welcome! Here we mean you are welcome.
Forms
Is this your bag?— your: it belongs to youYou're late.— you're: you areYour friends are here.— after your: a person or a thing
A common mistake
Wrong: Your welcome!
Right: You're welcome!
A common mistake is your welcome. We say: You're welcome!
More examples
You're my best friend.
You are my best friend, so: You're my best friend.
What's your name?
The name belongs to you, so: What's your name?