Je vais appeler l'ami John mais tu peux changer si tu veux:
Hello John,
I hope you're having a nice time, I wrote this letter to you because I want to tell you to stop smoking, and there are a lot of reasons for that: smoking may disturb the people around you as it smells and produces dust when you breathe it out, it is really bad for your lungs and can even produce lung cancer and other serious illnesses and it consumes a large amount of money per month as you buy more everytime you finish a pack and you want to smoke more and more as you smoke which only makes the effects worse.
See you soon,
your friend ........ .
