The way your toddler plays and handles his toys can tell you whether he's hitting the appropriate cognitive and developmental milestones for his age.
At 2, themes of play emerge and strings of imagination come together. Two-year-olds start to use their toys to put together short stories in unique ways.
For example, your child might make a square out of blocks - a sort of room. He puts a girl doll inside the room and says "Go home" as he brings a boy doll closer. "Knock, knock! Come in!" he says as he pushes one block aside to let the second doll enter the room. Then the two dolls embrace.
By playing out a scenario like this, your toddler demonstrates his ability to use symbolic play. That, in turn, brings out imitation, which shows that he understands how his world works. Unstructured toys like blocks help your child exercise his imagination. Give him time and space to create. Show interest, but don't probe too hard - he's not quite sure what he's up to, either.