This document outlines 14 guidelines for effective English language development (ELD) instruction based on research on English learners. The guidelines are grouped into those that are strongly supported by evidence and those that are emerging hypotheses. The strongly supported guidelines recommend that ELD instruction be provided daily with a focus on listening and speaking, explicit teaching of English elements, integration of meaning and communication, and corrective feedback. Emerging guidelines suggest maximizing English use while strategically using students' primary language, teaching language learning strategies, emphasizing academic language, continuing ELD through advanced proficiency levels, using language objectives, grouping by proficiency for ELD then mixing for other classes, and prioritizing ELD programs.