Answer
Probably time for a tune-up, spark plugs and wires..arcing ign. wires will make it jerk
good..of course, it could be the trans slipping..check the trans level when hot, engine idling in park. also, check the ign. wires by spraying some water out of a squirt bottle on them while walking..if it is
bad enough to jerk, you should be able to see/hear a spark going to metal before it reaches the spark plug.