This document provides an overview of topics covered in Module 1 of the California Teachers of English Learners exam, including language structure and development. It discusses the subsystems of language such as phonology, morphology, syntax, semantics and pragmatics. It also addresses factors that affect an English learner's language development like sociopolitical influences and the relationship between first and second language acquisition. Strategies are presented to help teachers address English learners' needs based on these linguistic concepts.