The No Child Left Behind (NCLB) Act of 2001 calls upon states to place a well-prepared teacher in every classroom. According to NCLB, "a prepared teacher knows what to teach, how to teach and has command of the subject matter being taught." To address the how-to-teach factor, many states have incorporated professional development in sheltered English instruction into their plans to meet the educational needs of English language learners. Each state's department of education should be consulted for information on the licenses, skills, knowledge, and professional development required for the qualification to teach in sheltered classrooms.
Content-area teachers can acquire the skills necessary for sheltered English instruction and may already practice many of the instructional strategies involved. Essential to sheltered instruction are teacher willingness and capacity to learn about and incorporate the prior knowledge of ELLs into instruction, to understand second language acquisition and address the linguistic needs of ELLs, to deliver comprehensible yet rigorous input, and to use spiraling and scaffolding techniques whereby every piece of information learned and every skill acquired provides the next-level substructure for building higher-order knowledge. To the extent possible, teachers also need to learn about students' culture and community and how these contexts affect students' ways of learning.