電気

1. Origins, structure, and basic meaning

• Structure: 電気 is read as でんき and is a noun for electrical energy or, in everyday expressions, an electric light.
• Basic usage: Turning off a room light appears in 電気を消す, while avoiding wasted electricity appears in 電気を無駄にしない.

2. Common pitfalls and similar expressions

• Both electricity and an electric light
  • It can denote the power used by a device or, with つける and 消す, the light in a room.
• Difference from 電源
  • Unlike the word for a power source, supply, or power switch, this term is used for both electrical energy and an electric light.