NEED HELP! CAN'T MOVE

Hey ppl i gotta problem...so i took my roomates pulsar (hasent moved in months) to work one cold alberta day and it made it there fine...when i was leaving work it stalled for no reason?? n e ways i was on the highway everything seemed alright then started hearing this faint high pitched grinding noise...i though it was a truck or something going bye then it started to get louder and i could eventually feel it so i started to slow down then all the sudden there was a somewhat boom and it was grinding like crazy so i pulled over and was on the side of the road...i tried to start driving i could get to 3rd then it would pop out...and eventually stopped moving alltogether.. so i went back to try to get it later on that night when there was less trafic and i would put the car in gear and it will not move nor stall out. but i can hear some grinding when i let go of the clutch but theres not even a bit of movement.. cars a junker but its not mine so i should fix it b4 buddy comes back now the question clutch or tranny?

Tim