The document discusses verbs and verb groups in English. It defines lexical verbs and auxiliary verbs. Auxiliary verbs can indicate tense, aspect, modality, or voice. There are two tenses in English - present and past. Future is indicated using auxiliary verbs like "will" rather than as a separate tense. Aspect includes perfect (have + past participle) and progressive (be + -ing). Modal auxiliaries do not indicate tense and are followed by the infinitive form of the verb. Primary auxiliaries are have, be, and do. The order of auxiliaries is tense/modal, perfect, progressive, passive. Do is used for negation, questions, and emphasis and is followed by the infinit