循環

1. Origins, structure, and basic meaning

• Structure: 循環 is a noun read じゅんかん for circulation through a continuing cycle and is also used as 循環する.
• Basic usage: It describes a person making room air circulate or water circulating through nature on its own.
  • 窓を開けて部屋の空気を循環させます。 describes opening a window to circulate the room's air; 授業で水が自然の中を循環する仕組みを学びました。 concerns learning how water circulates through nature.

2. Common pitfalls and similar expressions

• を循環させる
  • Before causative 循環させる, を marks the air that someone causes to circulate.
• が循環する
  • In 水が循環する, が marks water as what circulates on its own; distinguish this from the causative pattern.
• 循環 and 移動
  • 移動(いどう) broadly means moving from one place to another, while 循環 focuses on a flow that goes around within a continuing system.