All heck breaks loose: 18 months to 3 years
- Language explosion
- Brain develoment increases
- Children's language blooms into fluent grammatical conversation so rapidly that it's overwhelming
- No one has worked out the exact sequence.
- Sentence length increases steadily.
- The number of syntactic types increases exponentially, doubling every month, reaching the thousands before the third birthday.
- Normal children can differ by a year or more in their rate of language development.
- The stages they pass through progress in a similar way regardless of how stretched out or compressed.