My car clutch pedal keeps sticking to the floor, then flicks back up to normal possition.

hello,my car clutch pedal keeps sticking almost to the floor, then sometimes flicks back to the normal possition, i have to use my feet to bring the clutch pedal back to normal, i have a VW passat 2006 1.9 tdi, if you have any idea waht it is i would be happy,thank you