infernal dictionary

Infernal Language 101

Context: In our campaign we have made up the rule that infernal exists in two dictionaries. One for the typical conversational words and one solely for insults and swears, about twice as thick as the first that actually burns the tongue to speak are you not fiendish in nature. 

Insert a new character(A Human ronin) being introduced the other player(A Tiefling monk)

Ronin: So, what exactly is it that you do?

Monk: Well, I can punch things really good, I throw light bolts at things and I know about 10% of the second infernal dictionary. 

Ronin: Wait, there’s 2 dictionaries?!

Monk: Yeah, one for conversational infernal and one dedicated to swearing and insulting!

Ronin: …

Monk: …?

Ronin: Where’s this language been all my life?!