Use one object and one place
Put a toy in a box, on a table or beside a cup. Say the relationship once, then let your child move the object and notice what changed.
Offer two visible choices
Ask whether the toy is inside or outside, above or below, beside or far away. Pointing and moving count as answers just like words.
Connect the word to the room
Find one more example together, such as a shoe under a chair or a picture above a shelf. Stop after a few examples while the idea still feels clear.