why is my car fiat punto x reg hard starting?

im finding my car hard to start one min it works straightaway other times theres a slight pause then starts and other times completely nothing then straight after it kicks in again?? the other week wouldnt start at all,people had to jumpstart it every time, i put a new alternator on and it made no difference still had to jumpstart it, so i tried a new starter motor on and put a new lead connecting to battery had to jump it 1st time and it seemed to put power in battery slowly and seemed to work for a few days but tonight back to square one , i dont think its the battery as imy ignition lights are coming on also occasionally over revs any ideas anybody im stumped