Example 1: If a car's engine makes a strange noise, a mechanic checks it to find out what's wrong and fixes it.
Example 2: When a car has a flat tire, a mechanic can change it to a new tire so the car can drive again.
Example 3: If the brakes don't work well, a mechanic can fix them by replacing old brake pads so the car can stop safely.
Fun Fact: Mechanics use special tools to help them work on cars, just like a doctor uses tools to help people!