- This updated vocabulary-building book presents the essential core of words that students at middle-school and higher levels must know and be able to use fluently for academic success. These words also constitute essential vocabulary for ESL students and test-takers, as well as others who speak English as their second language. The authors present a series of brief word-building lessons, each introducing 12 new words that are presented in sample sentences and short articles. Fill-in-the-blanks exercises help students measure their word-building progress.