naoru-vs-naoru

Two words, one reading — なおる (naoru) is one of Japanese’s most confusing homophone pairs. Both 治る and 直る are read the same way, but they describe completely different kinds of “getting better.” Use the wrong kanji and you might say a broken machine “recovered from illness” — or that a sick person “got repaired.” This guide explains exactly when to use each word, with clear examples and a decision flowchart you can use right away.

Yuka

Hey Rei, what’s the best way to remember the difference between 治る and 直る?

Rei

The best trick is to associate each word with a strong image or situation. By the end of this article you’ll have one for each — promise!

At a Glance: 治る vs. 直る

治る (naoru) — To Recover, To Heal

治る is used when a person (or animal) gets better from an illness or injury. The subject is always a living being, and the “fixing” is biological — the body returning to a healthy state. The kanji 治 is also found in 治療 (chiryou, medical treatment) and 政治 (seiji, politics/governance) — both involve bringing something into order.

Example 1 — illness:

風邪が治った。
Kaze ga naotta.
My cold got better. / I recovered from my cold.

Example 2 — injury:

足のケガがやっと治った。
Ashi no kega ga yatto naotta.
My leg injury finally healed.

Example 3 — asking about recovery:

もう治りましたか？
Mou naorimashita ka?
Are you already recovered? / Have you gotten better?

Yuka

That makes sense! So 治る is about… okay, I think I’m starting to get it.

Rei

You’re getting it! And the more you practice using 治る in sentences, the more automatic it becomes. Language learning is all about repetition.

直る (naoru) — To Be Fixed, To Be Repaired

直る is used when an object, machine, or situation returns to its proper working state. It can also describe a bad habit that has been corrected, or a broken relationship that is patched up. The kanji 直 appears in 正直 (shoujiki, honest) and 直接 (chokusetsu, direct) — all carry the sense of straightening or correcting something.

Example 1 — machine:

パソコンがやっと直った。
Pasokon ga yatto naotta.
The computer finally got fixed.

Example 2 — habit:

遅刻する癖が直った。
Chikoku suru kuse ga naotta.
My habit of being late has been corrected.

Example 3 — situation:

二人の仲が直った。
Futari no naka ga naotta.
The relationship between the two of them was repaired.

Yuka

Alright. And now explain 直る? I want to make sure I have both down.

Rei

Sure! 直る is actually the easier one to remember once you have a clear mental image. Let’s look at the examples.

Side-by-Side Comparison

The Transitive Counterparts: 治す vs. 直す

Both 治る and 直る have transitive counterparts — 治す (naosu) and 直す (naosu) — which mean “to cure/treat” and “to fix/repair” respectively. These are also read the same way, so the pattern holds:

Note: The intransitive form (〜が治る／直る) means the subject changes on its own or naturally. The transitive form (〜を治す／直す) means someone actively causes the change.

Common Mistakes English Speakers Make

English uses “fix” loosely for both objects and health: “I fixed my cold” or “the doctor fixed my injury.” In Japanese, these two ideas are strictly separated by kanji. Here are the most common errors:

Mistake 1: Using 直る for a person’s illness.
✗ 風邪が直った。
✓ 風邪が治った。
Use 治る for illness — 直る implies a mechanical repair.

Mistake 2: Using 治る for an object.
✗ パソコンが治った。
✓ パソコンが直った。
Computers don’t “heal” — use 直る for things being repaired.

Decision Flowchart: 治る or 直る?

Something has returned to its proper state. Which なおる?
        |
        v
Is the subject a LIVING BEING (person, animal)?
   |                    |
  YES                   NO
   |                    |
   v                    v
Is it recovering    Is it an object, machine,
from illness or     habit, or situation?
injury?                 |
   |                   YES
  YES                   |
   |                    v
   v                  直る (naoru)
治る (naoru)          It was fixed / repaired /
It healed /          corrected
recovered

Quick Quiz — Test Yourself!

Yuka

Okay Rei, quiz time! I want to test how well I’ve absorbed all this.

Rei

Challenge accepted on your behalf! Let’s see how much of 治る and 直る has sunk in.

Choose 治る or 直る for each sentence.

Q1. My stomachache got better.
お腹の痛みが___。
Onaka no itami ga ___.

Answer: 治った (naotta)
Reason: A stomachache is a physical ailment in a living person — use 治る.

Q2. The broken window was fixed.
割れた窓が___。
Wareta mado ga ___.

Answer: 直った (naotta)
Reason: A window is an object — use 直る for repairs.

Q3. His bad habit of interrupting people corrected itself.
人の話を遮る癖が___。
Hito no hanashi wo saegiru kuse ga ___.

Answer: 直った (naotta)
Reason: A habit is a behavioral pattern — use 直る.

Q4. The skin rash has finally healed.
皮膚の発疹がやっと___。
Hifu no hasshin ga yatto ___.

Answer: 治った (naotta)
Reason: A skin condition on a person’s body uses 治る.

Q5. The air conditioner got fixed and is working again.
エアコンが___、また動いている。
Eakon ga ___, mata ugoite iru.

Answer: 直って (naotte)
Reason: An air conditioner is a machine — use 直る.

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あわせて読みたい

Now that you know the difference between 治る and 直る, explore their transitive counterparts 治す and 直す in more depth:

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Japanese is full of pairs that sound identical but mean different things. Check out another classic example — 速い vs. 早い (both read はやい):

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