Agitator and drum won't spin

The washer fills but when the wash cycle begins the agitator doesn’t turn and I hear a ratcheting type sound. When I turn the knob and go through all the other cycles all I get is the same sound. The washer will drain but the whole time it’s draining I still get the same sound and of course the close are sopping wet because the drum is not spinning. Any help would be truly appreciated because I don’t want to have to go with my wife to the laundrymat.