泣き顔

1. Origins, structure, and basic meaning

• Structure: 泣き顔(なきがお) combines 泣く with 顔 and denotes a crying or tearful face.
• Basic usage: It describes a lost child's tearful face turning into a smile upon finding their mother.
  • 迷子は母親を見つけると泣き顔から笑顔になった。

2. Common pitfalls and similar expressions

• Action and facial expression
  • 泣く(なく) describes the act of crying, whereas 泣き顔 is a noun for the visible facial expression. 笑顔(えがお) denotes a smiling face in contrast.