This handbook is a reference source on Estonian forms such as the singular and plural forms of nouns and adjectives or the various tense forms of verbs. Estonian relies extensively on the different forms that a given word can exhibit for indicating the grammatical relationships among the words in a sentence or text. For this reason the handbook is more extensive tha many comparable works aimed at native speakers. The materials in this handbook are arranged in such a manner so as to make it possible to discover that underneath the seeming chaos of Estonian forms, there is structure that is based on logic and regularity.