Japanese Compound-Word Pitch Accent: How Two Words Combine into One Accent Pattern
Japanese compound-word pitch accent is how two stems, once fused into a single prosodic word, lose their citation-form accents and receive a new one by rule.1 Knowing the rule turns thousands of unfamiliar compounds, including every new -人, -語, -化, and -家 word a learner will meet, from individually memorized items into predictable forms.1
Overview
For accent purposes, a compound noun is a sequence of two stems (N1 + N2) that surfaces as a single prosodic word with one accent, or none.1 The parts may be wago (native), kango (Sino-Japanese), gairaigo (loanword), or any mix. Either part may itself contain more than one morpheme.1
The compound is one phonological object, not two. Its accent is not the sum of N1's accent and N2's accent. It is reassigned.
What counts as a compound for accent purposes
The compound-accent rule covers noun-plus-noun fusions across all source-language combinations. It also covers productive Sino-Japanese suffixes (–家 -ka, –人 -jin, –国 -koku, –語 -go, –化 -ka, –的 -teki) that attach to a host stem.1 Verb-stem-plus-noun and adjective-stem-plus-noun forms behave similarly; their rules are treated in the sibling article on verb and adjective pitch accent.
The rule does not cover the phrasal noun-no-noun construction. A sequence like 田中さんの本 keeps its constituent citation accents and is not a single prosodic word.1 Two nouns linked by の are still two prosodic words.
The diagnostic is whether the sequence carries at most one HL pitch fall. If you hear two falls, you have a phrase, not a compound. Phrasal noun-no-noun keeps both accents; compounds collapse to one.1
The one-accent-per-prosodic-word principle
Tokyo Japanese permits at most one HL pitch fall per prosodic word. Kawahara, following Trubetzkoy and a long later tradition, calls this constraint culminativity.1 In Kawahara's words: "in the context of Japanese, the culminativity restriction means that there can be at most one accentual HL fall."1 This is a defining property of Japanese as a pitch-accent rather than a stress language: one drop, anchored to a specific mora, per prosodic word.
When N1 and N2 fuse, the compound is one prosodic word and therefore carries at most one accent.1 Kubozono and Mester state the consequence plainly: "the first member is deaccented (if it is lexically accented) and thereby loses its prosodic independence."2 Whether the compound's surface accent ultimately comes from N1, from N2, or is freshly assigned by rule, N1's citation accent is always deleted.2
The drop you hear in 携帯電話 is the compound's accent. It belongs to 携帯電話 as a single word, not to either 携帯 or 電話.
Why dictionary accents on N1 and N2 do not predict the compound
Looking up 携帯 [0] and 電話 [0] in a citation-form dictionary will not let a learner derive 携帯電話 [5] by composition.134 Two heiban inputs produce a nakadaka output. The arithmetic is not the rule.
OJAD's "compound noun" search exists for exactly this reason: the dictionary explicitly indexes compound surface accents because they do not fall out of N1-plus-N2 lookups.5
The core rule: accent location is governed by the second element (N2)
The Akinaga / McCawley generalization is short: the length of N2, not N1, decides where the compound's drop falls. If N2 is short (1–2 morae), the drop sits on the final mora of N1. If N2 is long (3+ morae), the drop sits on the first mora of N2, with a few exceptions tied to N2's own lexical accent.1267
That single split covers most productive contemporary kango compounds, including all new coinages built from –家, –人, –国, and –語, plus most loanword-plus-native combinations.1
Short N2 (1–2 mora): accent on the final syllable of N1
Kawahara states it directly: "short nouns are either monomoraic or bimoraic. They can behave in two ways: those that retain their accent, or those that assign accent on the last syllable of the N1."1 Kubozono and Mester's foot-based reanalysis arrives at the same generalization through a different formalism: "if N2=F, default compound accent on the last syllable of N1, i.e. on the penultimate foot."2 Here F means a foot, a unit of 1–2 morae in this analysis.
The default, and the most productive pattern for new and recent coinages, assigns the drop to N1's last mora, regardless of N1's or N2's citation-form accent.2
雨雲が出てきました。4
"Rain clouds have rolled in."
The compound is あ ま ぐꜜ も, nakadaka [3]. Both 雨 [1] and 雲 [1] are atamadaka in isolation, but the compound is [3]. The drop sits on N1's last mora, with rendaku riding along (くも → ぐも).14
Long N2 (3+ mora): accent on the first syllable of N2
Kawahara again gives the clean statement: "when N2 is trimoraic or longer, there are two major generalizations: (i) if N2 is unaccented or has accent on the final syllable, then the accent falls on the initial syllable of N2 […]; (ii) otherwise, the accent of N2 is retained."1 In plain terms, a long N2 usually pulls the drop to its own first syllable unless it already has a medial accent.
Worked example with an unaccented N2:
南アメリカの地理を勉強しています。1
"I'm studying the geography of South America."
南アメリカ is [4]: the drop sits on the first mora of アメリカ, exactly as the rule predicts for an unaccented long N2.1
When N2 already carries a medial (nakadaka) accent in isolation, the compound retains it instead of reassigning. しん + たまね'ぎ → しん たまね'ぎ "new onion" keeps N2's [4]; やまと + なで'しこ → やまと なで'しこ keeps N2's [3].1
Worked counterexample: 携帯 + 電話 = 携帯電話
This is the example learners often meet first and ask about most. Both inputs are heiban; the output is nakadaka. The arithmetic-minded prediction fails.
携帯 [0] heiban,4 電話 [0] heiban,4 携帯電話 [5] nakadaka: け い た い でꜜ ん わ.34
Under the long-N2 rule, N2 = でんわ is 3 morae (long N2) and unaccented. Therefore the default compound accent lands on N2's first syllable. The first syllable of でんわ is でん, a heavy syllable with a moraic nasal. The drop falls on its head mora で, yielding compound position [5].1
When the rule under-predicts: N2-type subclasses
Akinaga 1985 (incorporated in the NHK accent dictionaries) classifies N2s by their behavior in compounds. The typology has three productive types.79 The productive default for short N2 is "assign accent on N1's final mora"; some N2s have drifted further to "delete the accent entirely" (the modern -語 / -化 / -家 pattern); a small set of long N2s simply retain their own lexical accent.79
A few items are lexically marked exceptions even by the typology's own lights. Kawahara lists 研究所 kenkyū'sho "research center," 警察署 keisatsu-sho "police station," and ビタミンC bitamin-shi'i as compounds that retain N2's final accent against the general tendency.1 These must be memorized as items.
For day-to-day learning, the productive default plus a short list of recurring N2 morphemes is enough. The full typology is best left to OJAD, where each compound is indexed directly by its surface accent.5
Productive suffix classes you will meet weekly
Some Sino-Japanese suffixes are productive enough that a learner who knows the rule can predict the accent of any new compound built on them.9 The six most useful are –家, –人, –国, –語, –化, and –的. The honorifics –さん, –ちゃん, and –くん are not strictly compound second members, but they follow the same short-N2 mechanics, so they sit in this section with a hedge.
–家 (-ka): occupation / -ist
The traditional Akinaga rule predicts accent on N1's final mora before -ka.79 Modern dictionaries do not match that prediction for the most common occupational nouns. NHK 2016 and Daijirin record 政治家, 小説家, and 音楽家 as heiban [0].34
彼は政治家として有名です。4
"He is famous as a politician."
政治家 [0] heiban throughout: no drop. A learner predicting せ い ꜜ じ か [2] from the raw Akinaga rule will sound dated.4
The shift is a documented case of senmonka akusento (specialist accent), a deaccenting tendency that affects in-group occupational vocabulary. -家 is moving from Type 2 (N1-final) toward Type 3 (heiban) over generational time, faster for high-frequency items.1710 For productive new coinages, the safer modern bet is heiban. The historical Akinaga prediction holds best for old, low-frequency items.3
音楽家の家族に生まれました。4
"He was born into a family of musicians."
音楽家 [0] heiban (Daijirin records both ongakuka and ongakka variants, both [0]).4
–人 (-jin): nationality / person
The kango -jin attaches as a short N2 (1 mora) and follows the productive Akinaga pattern: accent on N1's final mora.79 This is the cleanest suffix in the family. Modern dictionaries match the rule's prediction without drift.
私は日本人ですが、英語も話せます。411
"I'm Japanese, but I can also speak English."
日本人 [4] nakadaka: に ほ ん じꜜ ん, with the drop on the fourth mora じ.4 The Waseda Toda pronunciation module states the rule as 「〜じん」で「じ」のまえでさがります ("in -jin compounds, the pitch falls before じ"). This is equivalent to "accent on the last mora of N1."11
アメリカ人の友達がいます。12
"I have an American friend."
アメリカ人 [4]; the drop sits on カ, the last mora of N1.12
外国人のための日本語クラスです。3
"It's a Japanese class for foreigners."
外国人 [4]; same pattern, drop on く, the last mora of 外国.3
–国 (-koku): country
The kango -koku attaches as a short N2 (2 morae), but its behavior is mixed because many -国 items entered the language centuries ago and have lexicalized. Treat individual country names as lexical items rather than rule outputs.
中国 has two recorded variants: [1] atamadaka (Shin Meikai) and [0] heiban (Daijirin).413 Broadcast standard and younger speakers default to [0]; older speakers and traditional NHK style use [1]. 韓国 is [1] atamadaka.4 外国 is [0] heiban.34
The kango -国 does not undergo rendaku: 王国 is ōkoku with a plain k.4 The voiced -guni in 雪国 is a different morpheme entirely: the native wago -kuni, not the kango -koku.48 The useful contrast is between kango -koku and wago -kuni:
雪国 has -kuni with rendaku to -guni. The suffix is native wago, follows wago fusion patterns, and behaves differently from any of the kango -国 country names.48
–語 (-go): language / word
Kango -go (1 mora) is the cleanest productive Akinaga Type 3 suffix, the type that deletes accent entirely. Any compound built with -語 surfaces as heiban [0], regardless of N1's lexical accent.19
日本語の勉強は楽しいです。4
"Studying Japanese is fun."
日本語 [0] heiban throughout, even though 日本 in isolation is [2].34 The -go suffix simply overrides.
中国語とフランス語を勉強しています。4
"I'm studying Chinese and French."
中国語 [0]; フランス語 [0]. Both heiban.4
–化 (-ka) and –的 (-teki): derivational suffixes
The kango -化 (2 morae, "-ification") was traditionally analyzed as taking accent on the syllable before the suffix, the standard Akinaga prediction.7 In contemporary NHK, however, most productive -化 coinages surface as heiban [0]: 国際化, 民主化, デジタル化 are all heiban in NHK 2016.3 The Akinaga prediction holds best for older items. The modern productive default has drifted to heiban.3
The kango -的 (2 morae, "-ic / -al") is the textbook deaccenting suffix. -的 deletes the root's lexical accent and makes the whole form unaccented, subject to the default L-H rise pattern.1
国際的 [0] heiban: -teki has deaccented the root 国際.34
One caveat: when -的 is followed by a copula or particle and the speaker emphasizes the adjective-like reading, a phrase-level pitch reset can produce a perceived drop on -te-. That is intonational, not lexical, and sits outside the compound-accent rule.1
–さん, –ちゃん, –くん attached to names
First, the hedge: -san, -chan, and -kun are not, strictly speaking, compound second members. The literature analyzes them as pre-accenting morphemes: affixes that are strong enough to insert accent on the syllable immediately preceding them, regardless of the host's lexical accent.1 In Kawahara's typology these sit alongside the suffix +ke ("family of"), where ono'+ke "family of Ono," yoshida+ke → yoshida'+ke, edogawa+ke → edogawa'+ke all show the same final-mora-of-N1 placement.1
The practical output matches the short-N2 rule: -san, -chan, and -kun all assign accent to the last mora of the name they attach to. たなか + さん surfaces as た な かꜜ さ ん, with the drop on か (the last mora of 田中).91 やまだ + さん → や ま だꜜ さ ん.91 The mechanism differs technically from the noun-plus-noun compound rule, but the surface output is the same.
A learner can keep the practical alignment without losing accuracy, as long as the morphological distinction is made clear at the start.
Sino-Japanese (kango) vs. native (wago) compound behavior
Kango compounds are the rule's most predictable cases. Wago compounds carry more lexical baggage: older items that froze before the productive rule stabilized, often with co-occurring rendaku as a fusion diagnostic.
Why kango compounds are the most predictable
The quantitative skew is dramatic. Among trisyllabic accented nouns in Kubozono 2008's database, Sino-Japanese nouns are 95% antepenultimate-accented. Native nouns are only 59% antepenultimate, 33% penultimate, and 9% final.1 Kango is tightly skewed; wago is variable. The compound rule applies most cleanly where N2 is kango.
Token frequency reinforces the picture: roughly 4,939 Sino-Japanese nouns vs. 2,220 native nouns in Kubozono's counted lexicon, with 51% of Sino-Japanese accented vs. 71% of native nouns unaccented.1 In compounding specifically, "Sino-Japanese words … almost always lose their N2 penultimate accent."1 Loanword N2s, by contrast, often retain their accent as a faithfulness effect.114
For a learner, this means: apply the productive Akinaga rule to kango compounds with high confidence. Treat wago compounds as items that more often need individual checking.
Why wago compounds carry more lexical baggage
Older wago compounds froze into the lexicon before the productive rule stabilized. Many are now memorized items rather than rule-generated forms. The chief diagnostic is co-occurring rendaku.8 When a compound carries rendaku, it has fused, and its accent often reflects an older state of the language, not the modern productive default.
山桜が満開になりました。4
"The mountain cherries have come into full bloom."
山桜 [3] yamaza'kura, with rendaku さくら → ざくら.4 さくら is 3 morae, so the long-N2 rule applies and predicts accent on N2's first mora ざ, exactly mora 3 of the compound. Here the productive rule and the lexicalized accent happen to agree. Both rendaku and the [3] pattern show that this compound is fully fused, not phrasal.18
春雨の音が聞こえます。4
"I can hear the sound of spring rain."
春雨 [0] heiban, with an unusual epenthetic -s- inserted between vowel-final 春 and vowel-initial 雨.4 The compound's surface does not follow either the short-N2 or long-N2 productive rule. It must be memorized.4
For more on this, see sequential voicing (rendaku). Rendaku and the compound-accent shift are formally independent operations, but they co-occur on the same items and both diagnose wago fusion.
Mixed compounds (kango + wago, gairaigo + native)
Mixed compounds default to the productive rule based on N2's identity, not N1's. When N2 is a productive kango suffix (–化, –的, –家, –人, –語), the kango pattern applies even when N1 is gairaigo.
アメリカ人 [4] applies the -jin rule to a loanword N1.12 フランス語 [0] applies the -go rule to a loanword N1.4 N1's source language is irrelevant; N2's identity drives the assignment.
When both N1 and N2 are gairaigo, the loanword N2 often retains its lexical accent (faithfulness). 新トヨタ keeps トヨタ's [1] atamadaka; ベスト + フレンド → ベスト + フレ'ンド retains フレンド's [2].1
The summary rule for mixed compounds: inherit kango predictability when N2 is kango, wago idiosyncrasy when N2 is wago.
Akinaga-style compound-accent classification
Akinaga 1985, as incorporated into the NHK accent dictionaries, classifies N2s into three productive types. The labels appear in TUFS and Waseda pedagogical material and indirectly in OJAD's compound entries. A learner who has seen them once will recognize them on sight.79
| Type | Behavior | Where it appears |
|---|---|---|
| 1 (自立型 jiritsu-gata) | N2 keeps its own lexical accent | Long N2s with medial accent: 新たまね'ぎ, やまとなで'しこ.1 Short N2s with penultimate accent: 高速バ'ス, 天然ガ'ス.1 |
| 2 (前部要素の最後の拍にアクセント核を移す型) | N2 assigns accent on N1's final mora | The default short-N2 case; the -人 family; many -国 items.79 |
| 3 (アクセント核を消す型) | N2 deletes the accent; compound surfaces heiban | The -語 suffix; the modern -化 default; the contemporary -家 drift.17 |
N2 type 1: keeps its own accent
The 自立型 N2 is strong enough that the compound inherits its accent unchanged.79 Long-N2 examples: しん + たまね'ぎ → しん たまね'ぎ (new onion, retains [4]); やまと + なで'しこ → やまと なで'しこ (Japanese lady, retains [3]); ベスト + フレ'ンド → ベスト フレ'ンド (best friend, retains [4]).1
Short-N2 examples exist too. These are N2s that retain their own penultimate accent against the productive default: 高速 + バ'ス → 高速バ'ス (highway bus); 天然 + ガ'ス → 天然ガ'ス (natural gas).1
N2 type 2: assigns a fixed accent on N2's initial mora
This is the default long-N2 case. N2 is unaccented or odaka in isolation, and the compound's drop lands on the first mora of N2.12 携帯 + 電話 → 携帯電話 [5]; 南 + アメリカ → 南アメリカ [4]; 早稲田 + 大学 → 早稲田大学 (drop on だ).111
早稲田大学に通っています。11
"I commute to Waseda University."
大学 [0] heiban as an isolated noun;4 in this compound the long-N2 rule places the drop on N2's first mora: わ せ だ だꜜ い が く.11
N2 type 3: assigns accent on the final mora of N1
This is the default short-N2 case in Akinaga's classification, though some sources confusingly number it "Type 2." N2 is one foot (1–2 morae); the drop falls on N1's last mora.29
This is also the case where many modern items have drifted further: from N1-final accent to outright deaccenting (heiban). That drift produces the contemporary -語 and -家 patterns.17
How to read N2-type information in OJAD and the NHK accent dictionary
OJAD does not display Akinaga type labels overtly; the types appear indirectly through the paradigm tables. The diagnostic workflow is simple: search the bare N2 to get its citation accent, then search two or three compounds built on it. If all compounds shift their accent to N1's last mora, the N2 is Type 2 or 3 (pre-accenting). If all compounds keep N2's lexical accent, the N2 is Type 1.5
The NHK 2016 dictionary (75,000 headwords, audio for over 100,000 items) indexes compound nouns directly, with their compound surface accents, and marks "2nd and 3rd stresses" where speakers vary.3 The dictionary does not label Akinaga types in its entries. Still, the entries themselves are the typology's empirical record.
A practical heuristic: when in doubt, look the compound up directly in OJAD or NHK. Do not try to compose accents from N1 + N2 lookups.35
Edge cases that diverge from constituent dictionary entries
A learner's instinct is to look up each constituent and add the accents. The compound rule defeats that instinct in three recurring shapes: two heiban inputs producing nakadaka, atamadaka N1 losing its accent, and old wago items whose accent simply froze.
Two heiban words producing a nakadaka compound
The 携帯 [0] + 電話 [0] → 携帯電話 [5] derivation is the canonical case.34 The same pattern appears wherever a heiban N1 meets a 3+ mora heiban N2: 大学 [0] is heiban in isolation, but 早稲田大学 takes accent on the first mora of 大学.411 The output's nakadaka [5] or [4] is not inherited; it is the long-N2 rule's output on unaccented N2.1
Atamadaka N1 losing its accent in compounds
雨 [1] + 雲 [1] → 雨雲 [3] amagumo.4 Both isolated forms are atamadaka, but the compound's drop sits at mora 3, ぐ. That is N1's last mora when the rendaku-voiced N2 is parsed as -gumo. N1's atamadaka [1] accent is gone. The compound's drop is the Akinaga rule's output, not a remnant of 雨's [1].14
Same logic for 中国 [1] (atamadaka) + 語 → 中国語 [0] heiban.4 N1's atamadaka is overwritten; -go's deaccenting property dominates.
Lexicalized compounds whose accent froze
Some compounds were borrowed or formed centuries before the productive rule stabilized. Their surface accents are historical residues rather than rule outputs.18
- 春雨 harusame [0] heiban, with epenthetic -s-, lexicalized.4
- 田中さん Tana'ka-san [3]: pre-accenting -san on a 3-mora N1, formally aligned with the productive rule but lexically robust.1
- 王国 ōkoku [0] heiban, no rendaku.4
For these items, the rule does not predict the modern surface; they must be memorized.
Why "the rule predicts the wrong thing" is usually a productivity issue
The productive rule describes new and recent compound formation. Lexicalized items are exceptions precisely because they entered the lexicon before the rule became the productive default.1 The modern senmonka akusento drift toward heiban (visible in the -家 paradigm above) is a productivity issue in the other direction: a Type 2 suffix shifting toward Type 3 over generational time.17
The pedagogical implication is clear. A learner should not "test" the rule against centuries-old wago items and conclude the rule is broken when it fails. Test the rule on contemporary coinages, productive Sino-Japanese suffixes, and predictable –語 / –人 / –化 / –的 derivations, where it works.
Good to know
Composing N1 + N2 citation accents mentally instead of applying the compound rule
The compound is one prosodic word with one accent. Citation accents of N1 and N2 are overwritten; they do not concatenate. A learner who looks up 携帯 [0] and 電話 [0] and predicts 携帯電話 [0] heiban by composition has made the wrong prediction. The Akinaga / Kubozono long-N2 rule reassigns the drop to N2's first mora when N2 is unaccented or odaka.134
The correct form:
携帯電話 [5] nakadaka: け い た い でꜜ ん わ.34
Assuming -家 still means "accent on N1's last mora" for modern coinages
A learner who has read older textbook accounts may expect 政治家 to surface as せ い ꜜ じ か [2] from the raw Akinaga rule. That prediction is now historical. NHK 2016, Daijirin, and Shin Meikai all record 政治家, 小説家, and 音楽家 as heiban [0]. The productive –家 suffix has drifted from Type 2 (N1-final) toward Type 3 (deaccenting) for high-frequency occupational nouns.17413 Treat the Akinaga prediction as historical context, not the modern target.
政治家と音楽家が会場にいます。4
"There are politicians and musicians at the venue."
政治家 [0]; 音楽家 [0]. Both flat.4
中国 has competing [0] and [1] entries across dictionaries
中国 is one of the more visible cases where citation-form dictionaries disagree. Shin Meikai records [1] atamadaka; Daijirin records [0] heiban.413 Younger speakers and contemporary news broadcasts default to [0]; traditional NHK announcer training kept [1] longer. This article foregrounds [0] for productive learner use. [1] is the variant a learner should recognize but not produce by default.413
Count N2's morae first, then place the drop
The full rule fits on one card. If N2 is 1–2 morae, the drop sits on N1's last mora. If N2 is 3+ morae and N2 is unaccented or odaka, the drop sits on N2's first mora. If N2 is 3+ morae and N2 is medial-accented, the compound retains N2's accent. Counting N2 first lets a learner pick the branch without ambiguity. That is why this is the right heuristic to internalize.2
The Akinaga rule's tidiness reflects historical re-regularization, not Middle Chinese tone
The rule's stability across the modern lexicon is partly a historical accident. When Sino-Japanese morphemes were borrowed, Middle Chinese tone categories were lost. Tokyo accent then re-imposed a uniform compound-accent pattern that did not exist in the source language. The "tidiness" of kango compounds today is the residue of that re-regularization, not preserved Chinese phonology.1
This is also why kango compounds feel tidier than wago compounds to a phonologist's ear. Kango fused into the Tokyo system later and more uniformly, while wago compounds were already lexicalized in older shapes by the time the productive rule stabilized.1
Treating the citation-form accent of N1 as the compound's accent
A learner who knows 日本 [2] and 人 [1] in isolation may predict 日本人 as [2], inheriting N1's drop. The compound is [4] nakadaka: に ほ ん じꜜ ん.411 N1's citation accent is deleted in compounding (Kubozono and Mester: "the first member is deaccented … and thereby loses its prosodic independence");2 the compound accent is reassigned by the N2-driven rule, not inherited from N1.
Pronouncing compounds with their citation-form accents is a foreign-learner tell
Pronouncing every new compound with its citation-form constituent accents is one of the clearest hallmarks of textbook-trained foreign Japanese. Conversely, applying the compound rule correctly is one of the easiest ways to sound less like a learner without studying any new vocabulary: no new lexical items required, just consistent application of one rule to compounds already known.
See also
- Japanese Pitch-Accent Notation: How to Read 0, 1, 2, 3 and the Overline Diagrams
- Japanese Pitch-Accent Minimal Pairs: The Drill List You Must Hear
- Regional Pitch Accent in Japanese: Kansai (Keihan), Tohoku, and the Accentless Dialects
- Should You Learn Pitch Accent? An Honest Cost-Benefit Analysis
- Jukugo (熟語): How Kanji Combine to Form Japanese Words
- Rendaku in Kanji Compounds: Why 紙 Becomes -gami