He was a young fellow, very green, very immature.

他是个年轻的家伙，没什么经验，很不成熟。

《柯林斯英汉双解大词典》

Come with us, young fellow!

来我们这儿，年轻人！

youdao

I could kind of feel the young fellow quivering.

我感觉到年轻的小伙子似乎在哆嗦。

youdao

"You better come with me,young fellow." " Don't take him away,officer."

VOA: special.2009.07.19

He used to stand in the city square in Athens, and talk with his fellow citizens, but he didn't chat idly with them, and he liked especially talking to young people.

他曾经站在雅典市的广场，和他的市民们说话，但是他并没有散漫的和他们说话，他尤其喜欢和年轻人说话。

麻省理工公开课 - 电影哲学课程节选

No matter how I look at this issue, I cannot escape being troubled by the fact that we have in place a policy which forces young men and women to lie about who they are in order to defend their fellow citizens."

VOA: special.2010.02.06

But when the 71-year-old senator is matched against the 46-year-old senator, the young fellow wins.

FORBES: Obama Is Better For McCain

"A young fellow who managed to escape was the one who told us about it, but we don't really know anything else, " Dominguez said.

CNN: 11 young people go missing from bar

Those bewitched by the John-John idea saw the grown man as a frivolous young fellow floating carelessly on the pleasures of life.

CNN: Brought up to be a good man