* Vocabulary grows at fastest rate during middle childhood
* Speed of growth facilitated by:
* Linking new words with ones previously knew (knowledge base)
* More sophisticated understanding of word meanings
* 6 years (1st grade) - 10,000 words
* 10-11 years (5th grade) - 40,000 words
* 20 years - 42,000 words
* 60 years - 48,000 words