The document discusses Cummins' Interdependence Hypothesis, which proposes that the development of proficiency in a first language (L1) facilitates the development of a second language (L2). It provides the definition of the hypothesis and explains some of its key principles, including that cognitive and linguistic abilities transfer across languages. It also discusses strategies for teaching English language learners, such as activating background knowledge, using cognates between languages, and organizing curriculum around themes to help students transfer knowledge.