A young/prime adult, according to Erik Erikson's stages of human development, is generally a person in the age range of 20 to 40, whereas an adolescent is a person aging from 13 to 19, although definitions and opinions vary. The young adult stage in human development precedes middle adulthood.

1. Young adults are increasingly choosing to delay marriage and focus on their careers.
   年輕成年人越來越傾向于推遲婚姻并專注于事業(yè)發(fā)展。
2. The book is categorized as young adult fiction and is popular among readers in their early twenties.
   這本書被歸類為青年成人小說，在20歲左右的讀者中很受歡迎。