暑い

1. Origins, structure, and basic meaning

• Structure: 暑い(あつい) is an い-adjective meaning that the weather or a surrounding space is hot.
• Basic usage: A present condition appears in 今日はとても暑い, while a room's past condition appears in 部屋が暑かった.

2. Common pitfalls and similar expressions

• Heat in the environment
  • Use it when the weather or an entire space feels hot, distinguishing this from the temperature of an object being touched.
• Past form
  • For the past tense, change the final い and use 暑かった.