This document discusses Sheltered Instruction Observation Protocol (SIOP), an instructional model that helps English Language Learners (ELLs) learn content material despite not having mastered English. It explains the eight components of a SIOP lesson and provides examples of differentiating instruction for ELLs at different language proficiency levels, from beginning to reaching, based on their ability to understand and communicate in English. The examples illustrate how to build background knowledge and provide comprehensible input for ELLs at each level in a sample SIOP writing lesson about the Reconstruction Era.