This popular children's chant is a great way to teach basic prepositions!

Let's go on a bear hunt. (Slap hands together.)

I see a wheat field.
Can't go over it. Let's go through it. (Move hands as if to part wheat.)

I see a bridge.
Can't go around it. Let's go over it. (Stack hands on top of one another.)

I see a lake.
Can't go over it, can't go under it, let's swim. (Make swimming motions with arms.)

I see a tree.
Can't go over it, can't go under it, let's go up it. (Climb with arms.)

I don't see any bears. (Look around)
Let's go down. (Pretend to climb down.)

I see a swamp.
Can't go over it, can't go under it, let's go through it. (Move hands as if to wade through swamp.)

I see a cave.
Can't go over it, can't go under it, let's go in. (Lean over as if to crawl through a small hole; slowly slap knees.)

I see two eyes. I see two ears. (Point to eyes; point to ears.)
I see a nose. I see a mouth. (Point to nose; point to mouth.)
Yikes! It's a bear! (Place palms on cheeks in show of surprise.)
Let's get out of here. (Quickly run backward.)