Ignition keys come in a variety of shapes and sizes depending on the make and model of vehicle you drive. When you encounter difficulty in turning an ignition key, it can be due to the wheel lock being engaged, the key being deformed or malfunctions inside the steering column.
A wheel lock is engaged when the car is in park, turned off and the steering wheel is turned a slight amount. It prevents car thieves from steering the car if they get it started.
A key that is either bent or has chipped teeth will be difficult to use in the ignition because it does not correctly fit the ignition switch anymore. Consider replacing the key at either a local hardware store or your local authorized dealer depending on whether your key has any electronics embedded in it or not.
Your car's ignition is a part of the overall steering column. If the rods connecting the steering wheel to the ignition are loose, missing screws or bent, you will have difficulty turning the key when it is inside the ignition.
