formal letter

[roseman]

Thank you in advance to help me
I need to write formal letter to professor to ask him if he can be supervisor on my PHD program. the problem that I can't write formal letter it's quite difficult .

[Gillnetter]

Thank you in advance to help me
I need to write formal letter to professor to ask him if he can be supervisor on my PHD program. the problem that I can't write formal letter it's quite difficult .

Yes, you are correct. Writing a formal letter may be difficult but getting a PHD is also difficult. I suggest that you start by writing something and posting it here for comments.