I’d say ask them what kind of things they want to do in the game – do they prefer combat, role-playing, political maneuvering, etc. Players need to learn to share when people have different styles at the table, but it doesn’t hurt to play to your audience as a DM.
Another trick can be to loop them in on worldbuilding and description. It can be as simple as saying “you find an object about the size of a melon. Describe it to us.” Or more complicated, like “The chancellor does not trust you, and has a hidden agenda – why doesn’t he trust you and what does he want?”
Another thing you might want to do is take a 10-15 minute break, especially with longer sessions. That can help people refocus, and it’s not a bad thing to get up and stretch your legs.