Réponse :
If it is a friend or someone close to your age you can greet them by their first name, like “Dear Alex”.
and to knew how to write a good one u should :
Begin the letter with a salutation. ...
Explain yourself. ...
Start with a question. ...
Share news. ...
Make it interesting. ...
Ask more questions. ...
Compose the last paragraph. ...
Choose a proper closing.
i hope that i helped u :)
