Little Timmy made that snowman all by himself. 小蒂米独自一人堆成了那个雪人。
Why did you leave your little brother by himself? 你为什么把你的弟弟丢下不管？
He spent all evening standing awkwardly by himself.
I asked my husband to help me tidy up but then my friend called, and he ended up doing it all by himself.
He is going to the barber's by himself for the first time today.
See also: himself (MALE)