独自一人

I was alone with no money or possessions.

我独自一人，没有钱，也没有财产。

He went to the bandits' lair all by himself!

他独自一人闯了土匪窝。

I work more efficiently on my own.

我独自一人工更高。

One can habituate oneself to living alone, though rarely with any pleasure.

虽然独自一人生活少会有乐趣，但还是可以。

He was alone in the house.

他独自一人在家里。

He was alone in the room.

他独自一人在屋里。

He was unhappy when alone.

他独自一人时感到不快活。