The greatest challenge inhibiting the ability of English-language learners (ELLs) to read at the appropriate grade level is perhaps a lack of sufficient vocabulary development. While extensive reading is beneficial, these students must acquire the necessary vocabulary in order to read extensively. Both vocabulary breadth and vocabulary depth are of equal importance to reading performance. The use of cognates, teaching the meaning of basic words, and review and reinforcement are important steps in developing the vocabulary of ELLs. Direct instruction in vocabulary, combined with word-learning strategies, was also found to be effective. Ultimately, vocabulary knowledge is a critical component of reading comprehension.