From Lameen Souag at Jabal al-Lughat, "Impersonal vs. personal 'you'", 9/9/2007:
Posted by Mark Liberman at October 2, 2007 06:12 AMIn English, "you" is equally used in a literal sense (referring to the addressee) or in an impersonal sense (referring to an arbitrary imagined experiencer.) In Darja, at first sight, it looks the same way - and for speakers of any one gender, this is true. However, looking at speakers of both genders allows you to realise that the distinction is grammaticalised. Addressee "you" agrees in gender with the addressee; impersonal "you" does not agree in gender with the addressee, but with the speaker. Thus a woman speaking to a man will say tṛuħ "you go" when "you" refers to the man addressed, but tṛuħi when it refers to an arbitrary person, like "When you go by bus, it takes a while."