An accent is the combination of phonetic properties attributed to words. English exhibits a stress system called a "stress accent (強弱アクセント)" in which syllables differ in how much stress is put on them. Japanese, on the other hand, has a "pitch accent (高低アクセント)" system in which syllables only differ in pitch.
To demonstrate how pitch accent is utilized in Japanese, consider the following example well-known to demonstrate how it is sometimes what makes sentences understood correctly.
L H H L H L L H H H H H H
As important as pitch might be to help bring clarity to a sentence, its use is not uniform throughout Japan. You should expect each major dialect to exhibit its own unique twist to the same formula. Some Japanese dialects don't even utilize pitch to distinguish words. The point of this lesson, however, is to become familiar with the Standard Japanese pitch accent system.
Technicality Note: It is humanly impossible to transition immediately from low to high pitch or vice versa. Changes are gradual with natural curvatures.
Unlike its neighboring language Chinese, Japanese is not considered to be tonal because pitch accent isn't fundamental to interpreting it. Pitch may be used to distinguish words every now and then, but this is not consistent throughout dialects, and pitch is not viewed as an intrinsic part of the language's lexicon. A foreigner could incidentally mess up the pitch of every syllable in a sentence and still likely be understood provided other aspects of pronunciation are fine. This is unlike Chinese in which messing up the tone of the world will inevitably change the word or make whatever you're attempting to say hard to understood.
As far as the rules of Standard Japanese's pitch accent system, there are four basic patterns to consider. These rules are designed with the forethought that affixes will attach to words. For instance, particles, auxiliary verbs, etc. influence the pitch accent of a phrase.
|頭高型||The pitch starts high, drops suddenly, then steadily goes down.||＼＿|
|中高型||The pitch rises, reaches a maximum, then drops suddenly.||／＼|
|尾高型||The pitch rises then drops when it reaches an attached element.||／￣（＼）|
|平板型||The pitch rises from start to end.||／￣（￣）|
ìmá (living room)
níhòN' (two long items)
Curriculum Note: IPA is used in this chart.
Kind / Syllable Count
1. 起伏 ＝ Highs and lows
2. 平板 ＝ Flat
|Rule 1||All こそあど expressions are 平板型.||ここ, それ, あの, こう, ああ|
|Rule 2||All nouns from 平板型 verbs are also 平板型.||あそび, たたみ, はじめ, たたかい|
|Rule 3||3 morae names from verbs → 平板型||イサム, シゲル,|
|Rule 4|| When the first part is 3(+) morae or 2(+) 漢字, |
compounds with the following at the end are
平板型: 色, 組, 型, 玉, 寺（てら）, 村, 山, 科, 家, 課,
語, 座, 派, 教, 産, 制, 線, 党, 病
| 血液型, 耳鼻科, 人事課, キリスト教, |
|Rule 5||Female names that end in 江, 枝, 恵, 代, 世||良枝, 正世|
|Rule 6|| Male names 3 morae (+) ending in 夫, 男, 雄, 助, 介, |
輔, 吉, 作
|正夫, 和男, 寿輔（じゅすけ）|
|Rule 7|| 4 morae onomatopoeic expressions with だ, に, or な|
|ざらざらだ, つるつるに, べたべたな|
|Rule 8||Nouns from compound verb expressions → 平板型||試合, 立ち入り, 買い戻し, 取り扱い|
|Rule 9||Interrogative are 頭高型.||だれ, なぜ, いつ|
|Rule 10|| 2 morae adjectives from the stems of adjectives |
|あお, しろ, くろ, あか, ふる|
|Rule 11||2 morae names → 頭高型||真理, 綾, 哲（てつ）|
|Rule 12||3 morae names from adjectives → 頭高型||敦（あつし）, 清志, 毅（つよし）|
|Rule 13||3 morae female names ending in 子 → 頭高型||喜世子, 華子, 千代子|
|Rule 14|| 3 morae male names ending in 樹, 吾, 二, 次, 治, 太, |
一, 市, 平, 兵衛, 郎 → 頭高型
|正樹, 信吾, 真二, 太郎, 四郎,|
|Rule 15|| 4 morae male names ending in 助, 輔, 介 → 頭高型 |
when the second morae is special, having a long vowel,
|庄助, 勘助, 泰輔|
|Rule 16||Onomatopoeia independent or with と → 頭高型|| はらはら（と）, でれでれ（と）, |
|Rule 17|| Compound words with the first half at least 3 morae or |
more than 2 漢字 → 中高型 ending with 子, 歌, 川, 豆,
虫, 器, 区, 市, 府, 部, 員, 駅, 園, 会, 海, 学, 群, 県, 省, 料,
| 受話器, 千代田区, 子守唄, |
|Rule 18|| 4 morae (+) male names ending in 彦, 介, 輔, 助 → |
|朝彦, 靖彦, 福助, 孝介|
|Rule 19|| 3 morae female names ending in 子 with the first morae |
devoiced → 中高型
|菊子, 比沙子, 富貴子, 芙紗子|
|Rule 20|| When verbs with 起伏式 pitch are sent to nouns, the |
pitch goes to 尾高型. However, if 4 morae (+), the word
could also be 平板型 or 中高型.
| 降る → 降り↓ 帰る（かえる） |
集まる（あつまる) → あつまり↓
|拍数||Type 1||Type 2||Type 3||Type 4|