Books in the "Clear Gramma"r series teach basic grammatical concepts, provide speaking and writing practice in grammatical structures and at varying cognitive levels, offer opportunities for students to check their progress, and serve as a grammar reference that is written with language and terms that lower-level students can understand without teacher assistance. Lessons focus on one specific grammar point and include grammar presentations, lists of potential errors with corrections shown, written exercises, speaking activities, multiple choice exercises, and review tests. Book 1 (beginning/high-beginning): the verb "to be," regular verbs, possessive adjectives, demonstrative adjectives, past tense of "to be" and regular verbs, wh-questions, word order, present progressive, count and noncount nouns, prepositions. Book 2 (high-beginning/low-intermediate): articles, "to be + going to," past tense of irregular verbs, how questions, frequency adverbs, object pronouns, "one/other," the possessive, words that compare, modals, problem words. Book 3 (low-intermediate/intermediate): two-word verbs, past progressive, present perfect, problematic time words, adverbs of manner, too/for, adjectives, used to, infinitives, gerunds, adverbs of purpose, sentence connectors, relative clauses. Book 4 (high-intermediate/low-advanced): past perfect tense, word forms, conditionals ("if" clauses and wish), adverb clauses, noun clauses, reduction of adjective and adverb clauses, past modals, subject-verb agreement, review of prepositions, and review of verb tenses.The workbook listed with each textbook is the companion workbook, designed to accompany and supplement the textbook as extra practice. Only the textbooks include the grammar instruction. To determine which level is right for your students, try the online placement test.