A boy was having a lot of difficulty in French class. 

To encourage him, his teacher said, "You'll know you're really beginning to get it when you start dreaming in French." 

The boy ran into class all excited one day, saying, "Teacher, teacher! I had a dream last night and everyone was talking in French!" 

"Great!" said the teacher, "what were they saying?" 

"I don't know," the boy replied, "I couldn't understand them."