What's happened to me?
-- Gregor. (Section I: Pages 1 - 11 paragraph 2)

Importance: Gregor's comment when he first begins to realize that something is very different about him this morning. He is still trying to reconcile the fact that this is not a continuation of the disturbing dreams he was having.

Gregor, the chief clerk has come round and wants to know why you didn't leave on the early train.
-- Gregor's Father. (Section I: Pages 1 - 11 paragraph 17)

Importance: Gregor's father is trying to impress upon him the importance of not only answering them, but opening the door so that they can assess his condition and determine a course of action.

Did you hear the way that Gregor spoke just now?
-- Chief Clerk (Section I: Pages 11 - 18 paragraph 3)

Importance: When the chief clerk from Gregor's employer makes this statement, it confirms for Gregor what he already suspects. His voice has changed as well as his body. It also tells him is that it has changed so much that they will have difficulty understanding him at all...