9. Don't tell lies to your boss or you'll be fired at once.
-> If
10. Don't be impatient or you will make mistakes.
- If
11. Study hard or you won't pass the exam.
=> If
12. You must tell me the whole truth or I won't help you.
-> If
13. Unless you promise to return back, I won't lend you.
⇒>>If
14. If you do not like this one, I'll bring you another..
-> Unless
15. I only come if they invite me.
=> Unless