 It can be fun for a child to learn about plants by talking about their differences. You can help them by pointing out two kinds of plants, like a flower and a tree, and saying, these are both plants, but how are they different? The child could say, the flower is small and the tree is big. You could say, the flower's stem is smooth and the tree trunk is rough. The child might say, the flower is red and the tree is green. This activity helps the child learn about the characteristics of different plants.