閉まる

1. Origins, structure, and basic meaning

• Structure: 閉まる (しまる) is an intransitive verb for a door, gate, or window changing to a closed state.
• Basic usage: 窓が閉まった reports a past event in which wind suddenly shut a window, while 門が閉まる describes an automatic routine that occurs each evening.

2. Common pitfalls and similar expressions

• The closing object is the subject
  • In 窓が閉まる and 門が閉まる, the object that becomes closed occupies the が position. Neither example contains a transitive construction in which a person closes it.