At 18 months old my granddaughter liked Granny to build a tower of Duplo blocks so she could knock it down and then say "again!" For several months that went on until I started using Duplo blocks as pretend food for her tea parties and I would build her things like cupcake with candle, slice of watermelon, blueberry cake with cherries on top, etc. At almost 2-1/2 now she has started building many things herself. She stacked 5 single blocks into a toy bucket and topped them with a round one and said "Granny I built a flower!" Next she wanted me to build a dinosaur but she quickly took it from me and finished it herself. She started linking them and laying them flat for roadway for her little cars and trucks. The best thing any adult can say about a child's toy is that it is safe, keeps them entertained for long period of time by themself and encourages creativity, learning and coordination skills.