Oxford Read and Imagine: Beginner: I'm Sorry

Oxford Read and Imagine is a fiction series written for primary and pre-primary students. Young learners follow Rosie, Ben and Grandpa on their adventures and grow up with the characters as they read and learn. Rosie, Ben, and Grandpa go to the park with Grandpa's robot, Clunk. Why does Clunk say, 'I'm sorry'?