You have an 11 month old grandson who lives with us that will not sleep througth the night you have tried a lot of things and nothing is working He takes maybe a one hour nap during the day?

See the doctor. He may be able to help. Also, try to get him outside more or doing some things to make him tired. Keep him napping, but make it before 2:00pm or so because if it is later, it can effect sleep.