What does Michael decide to do after he and Gertrud separate in Chapter 5?

After sending Hanna tapes for four years, Michael receives a written note from Hanna, thanking him for his latest story. Michael notices that the note looks as though it was written by a child, and though it is awkward, it signifies that Hanna was taking steps in learning to write. Michael realizes that he is proud of Hanna for learning to write.