 The former caretaker of the Overlook Hotel has two different names  (Charles Grady and Delbert Grady) because hes supposed to be two  different people. Charles is the caretaker who murdered his wife and  daughters in the winter of 1970, and Delbert is the butler of the  Overlook Hotel at the 4th of July party in 1921(which Jack was also  at). This is a reference to the original book (the former  caretakers name didnt change like it did in the movie, but he was  at the hotel in two different time periods