'说完' is a verb meaning 'to finish speaking' or 'to conclude what one has to say.' It combines the verb 说 (shuō, 'to speak') and the resultative complement 完 (wán, 'to finish/completely'). Together, they indicate the completion of the act of speaking — not just stopping, but having fully expressed one's point. This structure follows the common Chinese pattern Verb + 完, where 完 signals completion and often implies definitiveness or finality.

The word is frequently used in spoken and written Mandarin to mark transitions in conversation, storytelling, or explanations. It often appears before a pause, a change of speaker, or a follow-up action (e.g., '说完就走了'). While it can stand alone, it’s commonly followed by particles like 了 (le) to emphasize completed action, or used in clauses introduced by 一…就… ('as soon as…'). It carries no strong formality bias — appropriate in casual chats, classroom settings, and formal speeches alike.