When i attmpt to start my car it starts sometimes but sometimes it doesnt. is it the starter?

what happens when it dosent start a click dose it try to turn at all

it does not turn at all</ there is no nose at all and dose not trun over and the lights do not dim. We took the starter off had it checked and they said it was good, put it back on and it started. Next day went to the gas station put gas in it and nothing wouldn't start. Pushed it ten feet tryed it stated right up.