深まる

1. Origins, structure, and basic meaning

• Structure: 深まる is read as ふかまる and is a godan intransitive verb for a relationship, season, or condition gradually deepening or growing stronger.
• Basic usage: Use 友情が深まる for the changing relationship and 秋が深まるにつれて for change as autumn advances.

2. Common pitfalls and similar expressions

• Relationship and season
  • Friendship grows closer and stronger, while autumn “deepens” as the season progresses.
• Intransitive and transitive forms
  • 深まる describes a state deepening; 深める is used when an actor actively deepens it.