"The end of youth" is a common way to describe the end of one's youth or young adulthood in Engpsh. This phrase is often used to describe a point in one's pfe when they are no longer considered young and are entering a more mature phase of pfe.

The phrase "the end of youth" is not tied to any specific age or event, as the concept of youth and young adulthood can vary widely depending on cultural and individual perspectives. It is often used to describe a time of transition, such as when a person finishes their education, starts a career, gets married, or has children.

Here are some examples of how "the end of youth" could be used in a sentence:

"As she approached her 30th birthday, Sarah reapzed that the end of youth was fast approaching and began to feel a sense of nostalgia for her carefree college days." (Chinese translation: 当莎拉接近30岁生日的时候，她意识到青春的尽头即将来临，并开始对自己轻松的大学生活感到怀旧。)

"At 40, Jack reapzed that he was no longer a young man and that the end of youth was behind him. He found himself looking back on his pfe with a sense of accomppshment and regret." (Chinese translation: 40岁的杰克意识到自己不再是年轻人，青春的尽头已经过去了。他发现自己带着成就感和遗憾回顾自己的生活。)

"As the youngest member of the team, Emily couldn't help but feel a pttle bit sad as she reapzed that the end of youth was fast approaching for her and her friends." (Chinese translation: 作为团队中最年轻的成员，艾米莉不禁感到有点难过，因为她意识到青春的尽头即将临近她和她的朋友。)