Skills such as naming colors, showing affection, and hopping on one foot are called developmental milestones. Developmental milestones are things most children can do by a certain age. Children reach milestones in how they play, learn, speak, behave, and move (like crawling, walking, or jumping).
As children grow into early childhood, their world will begin to open up. They will become more independent and begin to focus more on adults and children outside of the family. They will want to explore and ask about the things around them even more. Their interactions with family and those around them will help to shape their personality and their own ways of thinking and moving. During this stage, children should be able to ride a tricycle, use safety scissors, notice a difference between girls and boys, help to dress and undress themselves, play with other children, recall part of a story, and sing a song.