What type of language use defines the second stage of first-language acquisition?

The second stage of first-language acquisition is characterized by the use of multi-word sentences. This stage, often called the "two-word stage," usually occurs around 18 to 24 months of age, when children begin to combine two words to express their thoughts and ideas. These combinations typically convey a variety of meanings, such as making requests or describing relationships (e.g., “more juice” or “mommy go”).

At this stage, children are moving beyond the use of single open-class words, which can provide limited communication, and instead start experimenting with word combinations that showcase their understanding of syntax and semantics. This developmental milestone reflects their grasp of how to connect words to create meaning, thereby marking a significant leap in their linguistic abilities. Using multi-word sentences indicates that children are on their way to forming more complex linguistic structures and expanding their vocabulary as they progress in their language development.