I tried to control myself and started to speak politely and in a friendly way.

politely 是形容词 polite（有礼貌的）加上后缀 -ly 构成的副词形式。polite 来自拉丁语 politus，原意是"打磨光滑的"，引申为"举止优雅的、有教养的"。 -ly 是常见的副词后缀，加在形容词后表示"以...的方式"。politely 意思是"有礼貌地"，描述说话或行为的方式。