治す

1. Origins, structure, and basic meaning

• Structure: 治す is read as なおす and is a transitive verb meaning to cure an illness or heal an injury.
• Basic usage: A doctor curing an illness appears in 病気を治す, while an herb healing an injury appears in けがを治す.

2. Common pitfalls and similar expressions

• Illness and injury take を
  • The illness or injury being healed is the object in 病気を治す and けがを治す.
• Difference from 直す
  • Although the reading is the same, 直す fixes objects or errors, whereas 治す is used for illness and injury.