Yes. The comma seperates any talking part from the part about the speaker, no matter the part. Though if there is nothing about the speaker, it is simply the speaking part. like this. It's just a cut part between two people, so one replying to another is simple to figure who is speaking.
Lol conversations were always my problem because I did not know about the commas. But in that last dailouge is the G after the comma suppose to be capitalized? And what does fd mean?
"I couldnt imagine."