速い

1. Origins, structure, and basic meaning

• Structure: 速い is read as はやい and is an い-adjective describing fast movement or action.
• Basic usage: Comparing train speeds appears in 普通列車より速い, while fast walking appears in 歩くのが速い.

2. Common pitfalls and similar expressions

• Comparing speed
  • The comparison target takes より, and the word applies when transport or an action moves at high speed or takes little time.
• Difference from 早い
  • Although pronounced the same, 早い means early in time or stage, while 速い means fast in movement or action.