Piaget's Theory of Cognitive Development explains four key stages that children go through as they grow up. These stages play an important role in how they learn language. Let’s break it down:

1. Sensorimotor Stage (0-2 years):

   • In this stage, babies learn through their senses and movements.
   • They start using gestures and sounds to communicate.
   • By around 12 months old, about 80% of kids can say their first words.

2. Preoperational Stage (2-7 years):

   • This is when kids start to think with symbols and use more language.
   • Their vocabulary grows quickly, going from about 200 words at 2 years old to around 3,000 words by age 5.
   • Children love to play pretend, which helps them use more complicated language.

3. Concrete Operational Stage (7-11 years):

   • At this point, kids start thinking logically about real things.
   • They understand more complex sentences and can talk about reasoning.
   • By age 8, kids can understand and use sentences that involve conditions, like saying "If it rains, I will stay inside."

4. Formal Operational Stage (11 years and up):

   • In this stage, abstract thinking and reasoning become very important.
   • Teens can talk about ideas that are not real, such as "What would happen if…?"
   • Studies show that by age 12, about 75% of kids are good at using language for complex ideas.

Overall, there's a strong link between how kids think and how they learn to talk. Research shows that as children reach these cognitive stages, their language skills improve too. Piaget believed that language reflects how well a child can think, showing that thinking and communicating are closely connected. This understanding helps in a child’s education and social skills as they continue to grow.