This document discusses participles in Korean grammar. It explains that participles are verb forms ending in -ing or -ed that can indicate tense when used with auxiliary verbs or act as adjectives modifying nouns. It distinguishes between present and past participles and how they indicate active/ongoing versus passive/completed meanings. It also discusses participial phrases where the beginning of the sentence is a participle, taking on adverbial meanings like time, cause, condition, etc. Examples are provided of how to construct participial phrases and considerations for subject-verb agreement.