In this course, we will explore several influential linguistic approaches to child language development (Optimality Theory, Universal Grammar theory, etc.). The main objective will be to demonstrate the predictive and explanatory potential of linguistic theories for analysis of child data. Some of the central questions that we will explore are as follows: What properties of human languages can be argued to be innate and what properties are learned from linguistic experience? Does language acquisition proceed without explicit instruction or do caretakers teach language to their children? Is there a critical period for various components of human language – phonology, syntax, semantics, pragmatics? We will consider how (psycho)linguistic studies of language acquisition provide some answers to these complex questions. How convincing these answers are is up to us to decide during this course.