Parts of speech are the building blocks of grammar and are classified into nine main categories: noun, verb, adjective, adverb, conjunction, preposition, interjection, article, and pronoun. The document provides details on the definition, identification, and formation of nouns, verbs, adjectives, and adverbs through inflectional and derivational morphemes. Nouns are names of people, places, things, or ideas and can take different roles in a sentence. Verbs express actions and take different forms to express tense. Adjectives describe nouns and pronouns and can be formed through suffixes. Adverbs describe verbs, adjectives, or other adverbs and can be formed through suffixes or