How does a guy communicate the difference between a friend who is a girl and a girlfriend in conversation?

How does a guy communicate the difference between a friend who is a girl and a girlfriend in conversation? As far as I know, the word is "Подруга" in Russian, but I can't find any distinction (and when I went to Russia, I couldn't get an answer on it either, ha)

You're right, the Russian word "подруга" does mean "a female friend". However, for a "girlfriend" people often use the word "девушка", e.g., "Она моя девушка" (She is my girlfriend). Sometimes Russian men, or women, will also use the word "друг" even referring to a female when they really want to stress that the person is just a good friend.
 

 

I wish I had been here for this! Natalya beat me to it :))). Well, Подруга is for "female friend" and of course "друг" is friend (and can be used for both genders). And in Russia they say моя девушка (lit. "my girl"), when they are talking about their girlfriend.