Introduction

Please consider the information from footnotes as optional, as they're not needed to understand the article. They contain either comments on decisions I made, or trivia for advance Japanese speakers.

Definitions

In order to facilitate and streamline the explanation of pitch accent behaviour in Japanese, the following terms are used

Mora

A mora is the shortest unit of length in Japanese phonology. Every open syllable is a mora, long syllables are two moras1, even if spelled with . and are also considered separate moras. A rule of thumb is, when written in kana, each character represents a separate mora (with an exception of small ゃゅょ and sometimes ぁぃぅぇぉ)

Word Reading Moras Mora count Explanation
先生 せんせい せ・ん・せ・い 4 is always a separate mora
優しい やさしい や・さ・し・い 4 is its own mora even though it makes long
合唱 がっしょう が・っ・しょ・う 4 is always a separate mora; しょ is one mora because only changes the vowel from i to o
です です で・す 2 is its own mora even if pronounced with voiceless u
パーティー パーティー パ・ー・ティ・ー 4 is always a separate mora (long vowels are two moras long); ティ is one mora because only changes the vowel from e to i
さぁ さあ さ・あ 2 Even though is a small kana character, it's used here to make long, therefore it is considered a separate mora

Phrase

A phrase is part of a sentence with distinct meanign and gramatical function, which has it's own pitch accent. Contrary to common belief, pitch accent doesn't apply to words but to entire phrases in a sentence. A phrase usually consist of a core meaning word (usu. noun/verb/adjective) and it's prefixes, suffixes, particles, and conjugation endings.

Let's look at this sentence:

山口さんは日本人ですか

Being very generous one could split this sentence into these separate words

山口 さん は 日本人 です か

However, this sentence consists of only two phrases:

山口さんは 日本人ですか

Where:

  • 山口さんは
    • 山口 – core meaning word (Yamaguchi - a surname)
    • 〜さん – suffix (honorific)
    • 〜は – particle (topic)
  • 日本人ですか
    • 日本人 – core meaning word (Japanese)2
    • 〜です – copula (to be)
    • 〜か – particle (question)

Therefore the whole sentence would be stressed like this:

 3

And not

     

Stressed mora

It's the last high mora before a downstep. Note that if there's no downstep (heiban), the final mora is not stressed. In this wiki, stressed moras are marked in red. Examples:

  • (先生) - is the last high mora, so it's stressed
  • - is the last high mora, so it's stressed
  • (花) - is the last high mora (the downstep is still there because it's odaka)
  • - no stressed mora ( is the last high mora but there's no downstep after it)

An expression "X is stressed" is equivalent to "X is a stressed mora", and by extension "X is the last high mora and after it there's a downstep"

Stressed word/phrase

It's a word/phrase which has a stressed mora. In practice, heiban is consider non-stressed and atamadaka, nakadaka, and odaka are considered stressed

Weak mora

It's a mora which cannot be stressed, even if it otherwise would following the regular rules. and are never stressed and therefore are considered weak. Additionaly, for some long vowels/glides the second mora is considered weak, but it's not always the case. Examples:

  • (先生) - and are weak moras
  • (多い) - the second is a weak mora as it's the second mora in the long o
  • (帰る) - is a weak mora as it's the second mora of the ae glide

In almost every case, when a weak mora needs to be stressed, the stress moves one mora back:

  • しゃ (社会人) not しゃ, because is a weak mora.

Types of phrases

Noun phrases

Stressed nouns

After stressed nouns, most postpositions will follow the low pattern:

  • 先生

Keep in mind it also applies to odaka:

One very important exception is 日本 when paired with 〜の:

  • 日本
    • !!!

Heiban nouns

After non-stressed (heiban) nouns, the behaviour is different based on how long the whole postposition is. If it's only one mora, it keeps its heiban pattern:

However, if the whole postposition is two or more moras long, the first mora of the postposition is stressed:

  • (continued)

Two important exceptions from this rule are 〜から and 〜だけ, which behave like one mora particles4:

  • (continued)

Na-adjective phrases

Generally, the same rules as for nouns apply. So for stressed na-adjectives the pattern continues with the low pitch:

  • 綺麗

While for heiban, only the first mora of the postposition is high:

  • 簡単

Note that the negation of na-adjectives (and also nouns for this matter) isn't considered a single phrase and therefore the above rules do not apply5:

  • 綺麗 (continued)
    • じゃ 
    •  
    •  
  • 簡単 (continued)
    • じゃ 
    •  
    •  

I-adjective phrases

The vast majority of i-adjectives are stressed, so for most of them the same rules apply

Stressed i-adjectives

Postpositions which are not changing the adjective (particles, です etc.) stay low:

  • 良い

Postpositions which change the adjecive (inflections) change the pitch pattern depending on adjective's length:

| Form | 2 moras | 3 moras | 4+ moras | | —- | ——- | ——- | ——– |

  • 悪い

And:

  • 楽しい

With the exceptions being:

  • 悪い (continued)
  • 楽しい (continued)

Obviously it doesn't apply if the i-adjective is only two moras long:

  • 良い
    • or

Heiban i-adjectives

A small group of i-adjectives have the heiban pitch pattern, but it's becoming more common for them to behave the same way as stressed i-adjectives, especially for younger native Japanese speakers. Heiban adjectives are only heiban when paired with postpositions or a noun directly after. Heiban nouns are still stressed when used at the end of a sentence on their own:

  •  
  •  
  •  

Verb phrases

Well, fuck

Examples

Hover over kanji to see furigana

明日(あした) ()せに ()きますよ
  

(わたし)は (ねこ)を ()って います
   

田中(たなか)さんは 毎日(まいにち) 東京(とうきょう)から 大阪(おおさか)まで 電車(でんしゃ)で (かよ)っています
  きょ  しゃ 

  1. A plural of "mora" can be both "moras" and "morae" (source). I will be using the first version as it's more in line with the English plural rules 

  2. Technically, this could be further split into 日本 and 〜人. I didn't do it here for 2 main reasons:

    1. Affixes change pitch patterns more significantly than regular postpositions (they usually force a certain pattern).
    2. 日本人 is an exception to the 〜人 accent rule anyway.

  3. Indicating a question by raising pitch at the end of a sentence is not a part of pitch accent analysis, and therefore will be omitted in examples. 

  4. The reason for this is that both 〜から and 〜だけ originally came from suffix nouns: 〜から comes from 柄 (origin, type) and 〜だけ comes from 丈 (height, limit) 

  5. Even more, if 〜じゃない is used for affirmation instead of negation (often further contracted to 〜じゃん), it is considered a postposition as a whole. This makes it a pitch accent minimal pair:

    じゃ – It's easy

    じゃ – It's not easy

    じゃ – It's pretty

    じゃ – It's not pretty