Locking the door is a great idea, whether you are at home or not, to prevent unauthorized people from entering and committing malicious acts. If this is your first time closing the door, fear not, as the task is easy and quick to accomplish.
Method 1 of 2: Locking from the inside
Step 1. Press down on the locking mechanism, which is a circular object in the center of the doorknob
Step 2. Turn the locking mechanism half a turn counterclockwise until you are no longer able to do this
Congratulations, you just locked the door
Method 2 of 2: Locking from the outside
Step 1. Take your key
All keys are different from each other, so you have to know which one is yours, or try each key until one fits.