There is this Russian language teacher I knew way back, and took his classes. He's a bit of a stickler about forms of address. I expect to meet him again in person in a few months.
How do I address him - in Russian?
I know his first and last names, and his professional title (he's got a master's degree), but don't know his father's name. Local customs usually mandate referring to university teachers as 'professors' even if they aren't entitled to professorship, as a honorific - but I don't know if it's the same way in Russia.