Science education in the Arab world is conducted in various multilingual contexts. When science is taught in Arabic, diglossia -- the coexistence of the formal language of literacy alongside a local spoken variety -- constitutes a multilingual setting the pedagogical implications of which need to be understood. This study compares teacher--student…

Research findings: Language development subcontexts within 20 Head Start classrooms were studied by observing teachers' child-directed talk during free play, mealtime, and book reading. In each context, observers coded all child-directed statements, directives, and questions, noted instances of pretend talk and decontextualized talk, and rated the…