At what age does the third stage of first-language acquisition typically begin?

The third stage of first-language acquisition, known as the "two-word stage," typically begins around 18 to 24 months of age. During this stage, children start combining two words to form simple sentences, such as "want cookie" or "more juice." This marks a significant advancement in their linguistic ability as they begin to understand and apply the rules of language to create meaning beyond single words.

This stage reflects children's increasing cognitive development and understanding of syntax—the structure of sentences. They move from using single words, typically seen in the earlier stages of language development, to more complex expressions that show their budding ability to convey ideas and desires effectively. This is a critical time in their language development as they explore communication more actively and begin to engage more meaningfully with their environment and the individuals around them.