How do you tell if clutch needs replacement?

You can tell if a clutch needs replacement by observing signs such as slipping, where the engine revs but the car does not accelerate properly. Other indicators include difficulty shifting gears, a spongy or vibrating clutch pedal, and unusual noises when the clutch is engaged or disengaged. If you notice any of these symptoms, it's advisable to have a professional mechanic inspect the clutch system.