talk to oneself  自言自语

　　I was talking to myself! 我在自言自语！

　　Sam's gone, and she was sitting here talking to herself like a crazy person. 山姆走了，她就坐在这里自言自语着，就像个精神异常的人。

　　Were you just talking to yourself? 你是在对自己说话吗？

　　Who was talking in the other room? 谁在房间里说话？

　　Suzy talks to herself sometimes.  苏琪偶尔会自言自语。