In the previous article we covered 直る vs 治る — the two verbs that share the reading なおる. Now let’s look at their transitive counterparts: 直す (naosu) and 治す (naosu). These mean “to fix” and “to heal” respectively — but someone actively does the action, rather than it happening on its own.
| 直す (naosu) | 治す (naosu) | 直る (naoru) | 治る (naoru) | |
|---|---|---|---|---|
| Type | Transitive | Transitive | Intransitive | Intransitive |
| Meaning | To fix / repair / correct (something) | To cure / heal (something) | To get fixed | To heal / recover |
| Who acts? | A person fixes the object | A person/medicine heals the condition | The object fixes itself | The body heals itself |
| Example | パソコンを直す | 病気を治す | パソコンが直る | 病気が治る |
直す — To Fix, Repair, or Correct (Something)
直す is the transitive version of 直る. Someone actively repairs a broken object, corrects an error, or fixes a bad habit. The particle を marks what is being fixed.
- パソコンを直す。— To fix the computer.
- 文章の間違いを直す。— To correct the mistakes in the text.
- 悪い癖を直すように努力している。— I’m making an effort to fix my bad habit.
- 自転車のタイヤを直した。— I repaired the bicycle’s tire.
Key: someone (you, a mechanic, a teacher) is doing the fixing to something else. Use を + 直す.
治す — To Cure or Heal (An Illness or Injury)
治す is the transitive version of 治る. A doctor, medicine, or the person themselves actively works to cure an illness or heal an injury.
- 早く風邪を治してね。— Get well soon (lit. cure your cold quickly).
- 医者が病気を治した。— The doctor cured the illness.
- 怪我を治すためにリハビリをしている。— I’m doing rehabilitation to heal my injury.
- 自分で傷を治そうとしている。— I’m trying to heal the wound myself.
Key: a person or treatment acts on a body/illness. Use を + 治す.
Transitive vs Intransitive — The Full Picture
| Situation | Transitive (active) | Intransitive (natural change) |
|---|---|---|
| PC repair | パソコンを直す (fixing it) | パソコンが直る (it got fixed) |
| Text correction | 文章を直す (correcting it) | 文章が直る (less common) |
| Illness | 病気を治す (curing it) | 病気が治る (the illness heals) |
| Bad habit | 癖を直す (correcting it) | 癖が直る (the habit gets fixed) |
Are you (or someone) actively doing the fixing/healing?
Physical object / habit / error → 直す (naosu)
Illness / injury / body → 治す (naosu)
Does it happen on its own / get fixed by itself?
Physical object → 直る (naoru)
Illness / injury → 治る (naoru)Natural Conversations
車、自分で直せるの？— Can you fix the car yourself?
ちょっとした修理なら直せるよ。— If it’s minor repairs, I can fix it.
早く風邪を治してね。無理しないで。— Get your cold cured quickly. Don’t push yourself.
うん、今日は早く寝る。ありがとう。— Yeah, I’ll go to bed early today. Thanks.
Common Mistakes
Mistake: Using 直す for healing an illness.
❌ 風邪を直す。
✅ 風邪を治す。
Mistake: Using 治す for repairing a machine.
❌ パソコンを治す。
✅ パソコンを直す。
Tip: The kanji 治 always relates to the body or medicine. 直 always relates to objects, text, or behavior.
Quick Quiz
Choose the right verb (直す or 治す):
1. 医者が骨折を___ために手術した。 (The doctor performed surgery to heal the fracture.)
2. プログラムのバグを___のに3時間かかった。 (It took 3 hours to fix the bug in the program.)
Answers: 1. 治す 2. 直す
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