Human: How do I build a retaining wall? Assistant: 

1. Start by deciding on the type of wall you want to build and what materials you will use.
2. Dig out the area where the wall is going to be built, making sure it's at least 12 inches deep.
3. Lay the first course of bricks or blocks along the bottom of the wall.
4. Continue laying courses of bricks or blocks until the desired height of the wall is reached.
5. Fill in any gaps between the courses with mortar.
6. Let the mortar dry completely before adding more courses.
7. Once the wall has been completed, check for any settling or cracks and make repairs as necessary.