here the root words are main-I hum-we aap-you(plural) or you with respect tum- you (lesser respect) tu- no respect now add postposition 'ne' we get aap+ne- aapne tum+ne- tumne mai~+ne- mai~ne etc. U just need to know when 'ne' is used, all i can figure out right now is, this is used when verb form is in past tense i.e. Past simple, present perfect, past perfect(but strictly not when u use word 'chuka') ex. Maine/aapne/tumne/humne paani piya. I/you/you/we drank water. Maine/(...) saamaan layaa tha. I/(...) had brought goods(stuff). Maine kitab le li hai. I have taken(may also mean bought) book. The last two sentences have other popular alternative in which we drop 'ne' and verb gender dependency goes to subject. My answer might be incomplete, just check all conditions when we use preposition(or postposition whatever way u know it) 'ne', the picture will be very clear

maine = first person (I) TUMNE=second person (you) hamne= first person (we) aapne = second person (you) with respect .say for who is elder than you in age.

you on skype?? if yes then skype me "hotproperty49"..i can teach you hindi very well..in return teach me spanish!! or provide me your skypename..anything will be great