Sensitive periods are when a child is drawn to specific topic in his or her environment. This can lead to repetitive behavior such as continuously picking out the same materials to work with, looking at the same book or constantly talking about a certain subject matter. When a child has a strong interest in a topic then that is the time to teach everything that is available within that subject. Concentration for long periods of a time is a good indicator when a child is truly interested in a topic. Learning new concepts within the child's interest will not only make lessons fun will but will come more natural for the child. Intrinsic sensitive periods include language (listening, speaking and learning new words) and a sense of order.