独自一人

• be on one's own
• be oneself

例句

1. 她并不因独自一人而稍有不悦。
   She wasn't any (the) less happy for being on her own.
2. 整日独自一人感觉如何？
   How does it feel to be alone all day?
3. （他）独自一人去游泳真是鲁莽。
   It was foolhardy (of him) to go swimming alone.
4. 你是说这都是你独自一人做的？
   You mean you did it all on your tod (ie without help)?
5. 今天我是独自一人。
   I'm all on my own today.