Japanese phonology refers to the sound system of the Japanese language. It is known for its relatively simple syllable structure, mora-based rhythm, and distinctive pitch accent system.

1. Phonemic Inventory

Consonants

Japanese has 15-18 consonants, depending on the analysis. Consonants are relatively simple, with no aspirated or voiced distinctions for stops (except nasality).

Vowels

Japanese has 5 vowels, which are relatively pure (monophthongal).

2. Mora-Based Rhythm

Japanese is a mora-timed language, where each mora (a timing unit) is of roughly equal length. Moras include:

• Vowels: /a/, /i/, /u/, /e/, /o/

• Consonant + Vowel (e.g., /ka/, /mi/, /su/)

• Nasal /n/: Independent mora (e.g., hon 本)

• Geminate consonants: Represented by a small "っ" (e.g., kitta 切った)

• Long vowels: Count as two moras (e.g., kō 高)

3. Pitch Accent

Japanese uses pitch accent, where the meaning of a word can change depending on the pitch pattern.

• High-Low: amé (雨) "rain" vs. áme (飴) "candy"

• The pitch pattern varies regionally, with Tokyo Japanese serving as the standard.

4. Syllable Structure

Japanese syllables are simple and conform to the CV (Consonant + Vowel) structure.

Allowed Structures:

1. V (vowel only): あ /a/

2. CV (consonant + vowel): か /ka/

3. CjV (consonant + glide + vowel): きゃ /kja/

4. N (nasal mora): ん /n/

5. Geminate (e.g., small "っ"): かった /katta/

• No Consonant Clusters: Japanese avoids clusters like "st" or "tr" that occur in English.

5. Special Phonological Features

Gemination:

• A small "っ" (e.g., katta 切った) represents a double consonant and adds an extra mora.

Nasal /n/:

• The final /n/ adapts its articulation based on the following sound:

o [m] before bilabials

o [ŋ] before velars

o [n] elsewhere

Pitch Neutralization:

• Some moras (e.g., particles like wa or ga) may lose their tonal distinction in connected speech.

6. Borrowed Words and Adaptation

• Japanese adapts loanwords into its syllabary (katakana). For instance:

o Computer → コンピュータ /kompyūta/

o Strike → ストライク /sutoraiku/

7. Writing and Phonology

Japanese uses three scripts:

• Hiragana (e.g., あ): Native words and grammatical markers.

• Katakana (e.g., ア): Loanwords and emphasis.

• Kanji (e.g., 本): Logographic characters.

8. Regional Variations

Japanese dialects differ in phonology:

• Kansai dialect: Different pitch accent patterns.

• Kyushu dialects: Voiced stops may not occur.