The document discusses finite and non-finite verbs in English grammar. Finite verbs show tense, person and number agreement with the subject, while non-finite verbs do not. There are three types of non-finite verbs: gerunds, which end in "-ing" and function as nouns; participles, which can function as verbs or adjectives; and infinitives, introduced by "to", which can function as nouns, adjectives or adverbs. The document provides examples and explanations of characteristics and functions for each non-finite verb form.