Form and use prepositional phrases.

Again, your kids do this instinctively. We form and use prepositional phrases all the time: "Remove your stinky socks from the table." They just need to remember the preposition and its object.

This is fourth grade, after all, so there's no need for long, drawn-out phrases. (The Scarlet Letter, we're lookin' at you.) If they can stand victorious atop some clean, simple, prepositional-phrase-filled sentences, they've got this one down.