Are you saying you can turn the steering wheel 1/2" before the road wheels actually turn, when the car is parked up? Or when driving in a straight line, it feels like there is 1/2" of play before the car reacts to steering inputs?
First scenario is worn parts. Outer tie rods, inner tie rods, rack, ball joints, wheel bearings etc. The usual suspects.
Second scenario is either the above, or knackered tyres, or worn bushes, or geometry or a combination of things.