can u tell me the difference between Fell out,fell down and fell off..

They can all be used to describe the physical act of 'falling' (and you might think that 'fell down' is an oxymoron - something that says the same thing twice - and sometimes it is, but usually to emphasise the fact of falling.) The differences are due to where the subject of the verb is to begin with or where they went when they fell. "I was standing in the train when suddenly the door opened and I fell out." "As the door opened I slipped and fell out of the train." "The lift fell down to the 3rd floor but was stopped by the emergency brake." "He was standing on the roof of the building when he fell off." 'Fell out' can also be used figuratively to mean having a disagreement [with] someone. "Because we could not agree, John and I fell out." "I have fallen out with Sarah because we always argue." There is yet another usage which is quite common meaning getting into (or sometimes out of) an orderly line. "The sergeant commanded the soldiers to fall in." (or "... to fall into line.") "The sergeant gave the command to 'Fall out!' and the soldiers were able to go their separate ways" Following on from this idea, one sometimes hears "By the time the director had explained the reasons behind his decision, everyone had fallen into line." meaning that all the employees (or members of the board) had understood and agreed to the decision.

Fell out - I fell out with my friend because she had been backstabbing me. Fell down - I fell down the stairs. Fell off - I was too engrossed in my conversation with a friend that I didn't notice I was standing too close to the edge of the cliff. That was why I fell off the cliff!