You learned that 人 is read 'hito'. Then you encounter 人々 and it's 'hitobito', not 'hitohito'. The 'h' becomes 'b'. Why? Welcome to the world of rendaku (連濁), one of the most confusing (but also most elegant) phenomena in Japanese.
What is Rendaku?
Rendaku (連濁) literally means 'sequential voicing'. When two words combine, the initial consonant of the second word can become voiced (dakuon). In practice:
- K → G: 国 (kuni) → some compounds use g sound
- S → Z: 空 (sora) → 青空 (aozora, not aosora)
- T → D: 時 (toki) → 時々 (tokidoki, not tokitoki)
- H → B: 花 (hana) → 花火 (hanabi, not hanahi)
- H → P (rare): 発 (hatsu) → 出発 (shuppatsu)
Common Rendaku Examples
| Base Word | Base Reading | Compound | Compound Reading |
|---|---|---|---|
| 人 (person) | hito | 人々 (people) | hitobito |
| 空 (sky) | sora | 青空 (blue sky) | aozora |
| 花 (flower) | hana | 花火 (fireworks) | hanabi |
| 時 (time) | toki | 時々 (sometimes) | tokidoki |
| 紙 (paper) | kami | 折り紙 (origami) | origami |
| 寿司 (sushi) | sushi | 巻き寿司 (maki sushi) | makizushi |
When Does Rendaku Apply?
Here's the problem: there's no strict rule. Rendaku is more a tendency than a law. But there are some patterns:
General Tendencies
- Native Japanese words (和語): rendaku frequent
- Chinese-origin words (漢語): rendaku less common
- Foreign words (外来語): almost never rendaku
- Coordinate compounds (A and B): often rendaku
- Descriptive compounds: depends
When NOT to Apply: Lyman's Law
There's a rule that BLOCKS rendaku, called 'Lyman's Law': if the second word already contains a voiced consonant (g, z, d, b), rendaku doesn't apply.
- 風 (kaze, wind) already has 'z' → 神風 = kamikaze (not *kamigaze)
- 傷 (kizu, wound) already has 'z' → doesn't change
This rule works about 80% of the time. The remaining 20%? Exceptions you need to memorize.
Other Factors Affecting Rendaku
- Old compounds: more likely to have rendaku (they've 'fused' over time)
- New compounds: less likely (still perceived as two separate words)
- Proper nouns: often preserve original form
- Onomatopoeia: almost always rendaku (ドキドキ, ガタガタ)
- Repetition of same word: often rendaku (人々, 様々, 時々)
Common Words with Rendaku to Memorize
- 青空 (aozora) - blue sky
- 花火 (hanabi) - fireworks
- 手紙 (tegami) - letter
- 時々 (tokidoki) - sometimes
- 人々 (hitobito) - people
- 日々 (hibi) - days, daily
- 様々 (samazama) - various
- 巻き寿司 (makizushi) - sushi roll
- 居酒屋 (izakaya) - izakaya (pub)
- 鼻血 (hanaji) - nosebleed
How to Learn Rendaku
Don't try to memorize rules. Learn word by word. Over time, you'll develop an intuition for what 'sounds right'. Here's how:
- When learning a new compound word, note if there's rendaku
- Read and listen a lot: exposure builds intuition
- Don't stress too much: even Japanese people sometimes make mistakes
- When in doubt, don't apply rendaku: it's the less serious error
Conclusion
Rendaku is one of those phenomena that seem impossible to understand at first, but become natural with exposure. It's not something to 'study' so much as 'absorb'. Every time you learn a new word with Kanjidon, note the reading. With thousands of words, the pattern emerges on its own.
