Can't figure it out. Help

My daughter has a 1988 Chevy Celebright 4-door car. She pulled up to a stop sign and the transmission quit working. I brought it home and it runs if the front end is off the ground but it will not pull the car. What can the problem be.

Sorry that should be a Chevy Celebrity. My spelling was not good.

check your fluid level first. Then maybe change the filter and fluid in the tranny. If that don't work your looking at a scrap yard for a tranny. JMO