Can you describe what you think about or do when you're introverting? Are you in an imaginary world, mentally/physically organising things, reading books, on the internet or are you enjoying a movie by yourself? Or is it more like a sort of mental fog that still recharges you? How does being alone help you?
Extroverts can respond as well - I'm kind of interested in seeing how Fi, Ni, Si and Ti manifest in terms of understandable examples of behaviour, and Aux functions are fine by me.