Understand and correctly use the positional words on, under, and beside.
Position words tell you WHERE something is - on top, underneath, or right next to something else.
On means touching the top. Under means below something. Beside means right next to it.
Mastery looks like: Child correctly follows and uses the position words on, under, and beside when placing or describing objects.
Common stumbles: Child confuses beside with in front of or behind, since all three describe "near" rather than on top or underneath.