Theories of language development differ, name and describe. some of them.

1. Nativist theory. Emphasis hereditary and suggests that all humans are genetically wired to learn a language (Chomsky, 1972, 2006). 2. Behaviourism. Suggests that children learn language through practice and reinforcement (Skinner, 1953, 1957). For example, a 2-year-old picks up a ball and says, "Baa." Mom smiles broadly and says, "Yes, ball! Good job!". Mom saying "Good job!" reinforces the child's efforts, and over time, language is shaped. 3. Social cognitive theory. Emphasises the role of modeling, feedback, and children's imitation of adult speech (bandura, 1986, 2001; Balog, 2010). For example, the father models an expression "Give Daddy some fruit.", the child attempts to imitate it, and he expanded and refined it. 4. Vygotsky's sociocultural theory. Suggest that children learn language by practicing it in their day-to-day interactions with others, and adults adjust their speech to operate within childrens' ZPD (Karniol, 2010). For example, infant-directed speech, uses simple words, short sentences, and voice inflections to provide linguistic scaffolding for young children. As their children's language skills advance, parents use bigger words and more complex sentences which adjust the process to each child's changing ZPD (Lieven & Stoll, 2010; Sterponi, 2010).