在这个上下文中,可以使用这样的表达来描述某人自己回来了:

"He came back on his own."

这个表达的来源可以归因于英语中的动词"come back",意思是"回来"。它是一个短语动词,由动词"come"和介词"back"构成。"Come"意思是"来","back"意思是"向后"。因此,"come back"的意思就是"从某个地方回来"。

在这个表达中,"on his own"是一个短语,意思是"独自一人"。这个短语用来表示某人没有借助任何人或任何帮助就自己回来了。

下面是一些英文例句及其中文翻译,希望能帮助你理解这个表达:

"I was worried when he didn't come home last night, but he came back on his own this morning."
(昨晚他没回家我很担心,但今天早上他自己回来了。)

"She left the party early, but she came back on her own a few hours later."
(她早早就离开了聚会,但几个小时后她自己回来了。)

"He left the office for a meeting, but he came back on his own after it ended."
(他去开了一个会议,但会议结束后他自己回来了。)