Calling them by name in a friendly tone of voice will usually stop their forward motion and capture their attention.
Helping them move around is made easier by their compliance with non-verbal gestures, including come and follow me. Patting the seat on a chair or a sofa seems to be a universal invitation to sit down. Patting on a bench, bed or sofa beside the person may be a universal invitation to scoot over.
Their language includes the names of the rooms and the activities to be done there.