Source: Scientific American, Sep 2016
The research suggests a radically different view, in which learning of a child’s first language does not rely on an innate grammar module. Instead the new research shows that young children use various types of thinking that may not be specific to language at all—such as the ability to classify the world into categories (people or objects, for instance) and to understand the relations among things. These capabilities, coupled with a unique human ability to grasp what others intend to communicate, allow language to happen.
… young children begin by learning simple grammatical patterns; then, gradually, they intuit the rules behind them bit by bit.
Thus, young children initially speak with only concrete and simple grammatical constructions based on specific patterns of words: “Where’s the X?”; “I wanna X”; “More X”; “It’s an X”; “I’m X-ing it”; “Put X here”; “Mommy’s X-ing it”; “Let’s X it”; “Throw X”; “X gone”; “Mommy X”; “I Xed it”; “Sit on the X”; “Open X”; “X here”; “There’s an X”; “X broken.” Later, children combine these early patterns into more complex ones, such as “Where’s the X that Mommy Xed?”
usage-based linguistics, has now arrived. The theory, which takes a number of forms, proposes that grammatical structure is not innate.
Instead grammar is the product of history (the processes that shape how languages are passed from one generation to the next) and human psychology (the set of social and cognitive capacities that allow generations to learn a language in the first place). More important, this theory proposes that language recruits brain systems that may not have evolved specifically for that purpose and so is a different idea to Chomsky’s single-gene mutation for recursion.
In the new usage-based approach (which includes ideas from functional linguistics, cognitive linguistics and construction grammar), children are not born with a universal, dedicated tool for learning grammar. Instead they inherit the mental equivalent of a Swiss Army knife: a set of general-purpose tools—such as categorization, the reading of communicative intentions, and analogy making, with which children build grammatical categories and rules from the language they hear around them.