By what age are trends in a child's amount of talk and vocabulary growth well established?

The correct response indicates that by age three, a child's amount of talk and vocabulary growth is well established. At this age, children typically exhibit significant advancements in their language skills. They are not only increasing their vocabulary but also beginning to use more complex sentence structures and demonstrating more sophisticated communicative abilities.

Research shows that by this time, children can use language to express thoughts, ask questions, and engage in conversations, reflecting their understanding of how language functions in social contexts. This pivotal period is critical for early literacy development; thus, the emphasis on establishing a strong foundation in vocabulary and communication skills by age three is well supported in early childhood education and developmental literature.

In contrast, earlier ages, such as one and two years, are marked by rapid language acquisition but are still foundational stages. At age one, children are typically babbling and may say a few words, and by age two, their vocabulary is growing but still limited compared to later stages. By age four, while children have a more advanced vocabulary and conversational skills, the trends in their language development have already been established during the prior years, making age three the pivotal timeframe for observing these trends in a structured manner.