Japanese Verb Pitch Accent Statistics
69.1% of Japanese verbs are accented; frequently used verbs tend to be flat.
The Data
All verbs from my JLPT deck (N5 through N1), excluding:
- サ変動詞 (noun + する verbs like 勉強する)
- Polyphonic entries (words with multiple pitch patterns like 致す (②, ⓪), 差し上げる (⓪, ④))
The pitch accent is notated using circled numbers where:
- ⓪ (Heiban/Flat): Pitch rises after first mora and stays high
- ① (Atamadaka): First mora high, then drops
- ②③④… (Nakadaka): Pitch drops after the indicated mora
Overall Results
| Level | Total | Heiban (⓪) | Atamadaka (①) | Nakadaka (②+) |
|---|
We see a very interesting trend: lower level verbs tend to be heiban. It’s safe to say that frequently used verbs are more likely to be heiban, reaching roughly 50% at the N5 level.
Testing the [-2] Hypothesis
A commonly cited rule: verbs tend to have their pitch drop on the second-to-last mora (the [-2] position).
For a 3-mora verb like かくす, this would be ②. For a 5-mora verb like あたためる, this would be ④.
Results:
So yeah, the hypothesis holds some water.
Detailed Breakdown by Pitch Number
| Level | Total | ⓪ | ① | ② | ③ | ④ | ⑤ | ⑥ |
|---|
Following Up
Would be interesting to weigh the verbs by frequency to produce an “effective” pitch accent distribution.
Raw Data
Non-Compound Verbs (1183)
Compound Verbs (349)
*Compoundness is determined with LLM, mostly accurate with minor mis-classifications.