This document provides an overview of first language acquisition and approaches to studying it. It discusses: - The stages of telegraphic speech and order of acquiring grammar morphemes in early language development. - Language milestones from preschool to school-aged years, including developing question-asking, storytelling abilities, and understanding different language registers. - Three approaches to studying native language acquisition: behaviorism, innatism, and interactionism. Behaviorism emphasizes environment/imitation, innatism innate linguistic knowledge, and interactionism the role of both nature and nurture.