Children develop language concepts through play. Introduce your child to the concept of 'thick' and 'thin' with this simple activity. Place a thick roll of toilet tissue, (full roll), in your child's hand and say the word, "Thick". Do the same with the thin, (empty roll), and say the word, "Thin." Play "Hide and Seek" with the rolls. Ask your child to hide each roll. Use the words frequently as you locate other 'thick' and 'thin' objects. Reinforcing language will help your child develop concepts.