One who is particularly particular about the accuracy of grammar, punctuation and syntax.
Tony:"At the end of a sentence, should I use a single space or two?"
James:"I heard people are now using just one."
Chris:"What?? That's crazy, I was taught it was ALWAYS two!!"
Muffy:"Dude, just ask my professional writer/columnist/blogger friend Mandy, she's a total grammando, so she should know."