开始 (kāi shǐ) is a verb meaning 'to begin' or 'to start.' It combines two characters: 开 (kāi), which means 'to open' or 'to initiate,' and 始 (shǐ), meaning 'to begin' or 'origin.' Together, they reinforce the idea of initiating an action or event — much like saying 'open the beginning.' It’s commonly used for starting activities, processes, meetings, classes, or even abstract concepts like relationships or projects.

This word functions as a transitive verb and usually takes a direct object (e.g., 开始工作, 开始学习). It can also appear in compound structures like 开始了 (has begun) or 正在开始 (is beginning). Unlike some other verbs, 开始 is neutral in register — appropriate in both spoken and written Chinese, from casual conversations to formal reports. It’s rarely used as a noun; when nominalization is needed, people say 开始的时候 (at the beginning) or 起始 (a more literary synonym).