hey there ,i m really desperate concerning the connection between dharma and the others.i really havent gotten it right...how do we know whats going on between those two?are we certain the others arent dharma???how?please,id appreciate any help

As of now, I don't think the Others are/were Dharma.

I think we got a clue about why this week, when Locke blew up the submarine and Ben allowed him to. Ben had also manipulated Locke into not pressing the botton in the Hatch, which caused the EMP that knocked out the SatCom at the Flame and the Sonor for guiding in the Sub, thus isolating the Island further. We all know the Island is a special place with strange powers. It's possible that a few of the Others started as Dharma but we haven't seen anything to indicate this.

The Others obviously have their own agenda, and now they get to keep a neuro surgeon and a fertility expert. This season has just heated up fast!