The Preoperational Stage
At this stage children begin to think symbolically and learn to use words and pictures to represent objects. And while they are getting better with language and thinking, they still tend to think about things in very concrete terms.
The foundations of language development may have been laid during the previous stage, but it is the emergence of language that is one of the major hallmarks of the preoperational stage of development. Children become much more skilled at pretend play during this stage of development, yet still think very concretely about the world around them.
At this stage, kids learn through pretend play but still struggle with logic and taking the point of view of other people. They also often struggle with understanding the idea of constancy.