It's not silent in classical Latin, just like it's not silent in English. It's /h/ and [h]; it's not supposed to be /x/ and [x]. In Latin, ⟨H⟩ was written to denote the fact that you must read it out loud with [h]. The only time that it's not phonemic in English is in clitics and certain words of French origin, like "hour", "hors d'oeuvres", or "heir". It's even pronounced in "hospital".
Hi, not sure if you still need the help :) But, as far as I know: habitas --> second person singular (you) present tense indicative of habitare habitatis --> second person plural (you) present tense indicative of habitare habitasne --> habitas + ne (ending, which is used to ask a question and usually added to a verb at the beginning of a sentence)
Greetings from Germany :)
Conjugation of the present tense indicative of habito:
So "I live in Italy" is "In Italia habito" and "You live in Italy" is "In Italia habitas" if speaking to one person, or "In Italia habitatis" if speaking to more than one person.