One day, John was back home after work. He found that his wife was shaking their daughter who was only half a year old. She said "Da-Dy" to the baby many times. John felt very happy because he thought his wife chose the word "Dady" to teach their baby. During one night several weeks later, John and his wife were waken up by the cry "Dady". His wife said to him, "Darling, she is calling you." Then she turned to sleep.