the pronunciation is just different depending upon different places like whether in Swat, Pekhawar and so on... there 2 dialects in pashtu beasically... refer to basic pashtu course ... u will get all ur ansawers regarding this there....
za mean go
and also
za means "i"
der is very
kha is good..
za der kha yam... i am very good....

and i dont stay there at all.. in fact have never been there ever.... my grandparents were born and brought up there.... its my native...