痛い

1. Origins, structure, and basic meaning

• Structure: 痛い is read いたい and is an adjective expressing bodily pain.
• Basic usage: It is used for a knee hurt in a fall or a throat that has been sore since morning.

2. Common pitfalls and similar expressions

• Negative and past forms
  • The negative form, meaning that it does not hurt, is 痛くない(いたくない).
  • The past form, meaning that it hurt, is 痛かった(いたかった).