Language development is an important part of how children grow and learn. Here are some key points about this process:

1. Growing Vocabulary:

   • By the time a child is 2 years old, they usually know about 200 words.
   • By age 5, their vocabulary can grow to around 2,500 words.

2. Thinking Skills:

   • Studies suggest that there’s a strong link between how well kids use language and their IQ. This means that kids with good language skills often have higher thinking skills, with a connection score of $r = 0.70$.

3. Best Learning Time:

   • Research shows that the best time for children to learn a language is before they turn 7. This is when their brains are really good at picking up new things.

These points show how closely language learning connects with how children think and grow.