When I was about 13 my English teacher showed us a picture of some children playing in a park. All was going well – I could understand what she was saying, and felt very clever – when she suddenly said something that startled and puzzled me so much that I just stopped paying attention to everything else. She’d pointed to a boy in the picture and said: Johnny is sitting on the bench. “What?”, I thought. “Johnny is not sitting at all!” What happened was that in my...