Introduction ー Why is 「は」 written as ha but pronounced as wa?
One of the earliest puzzles that Japanese learners encounter is the particle 「は」.
In writing, it appears as ha, yet in speech it is pronounced wa. For example, “私は学生です” is pronounced Watashi wa gakusei desu, not Watashi ha….
This phenomenon is not a random exception. It reflects the long history of sound changes in Japanese, the conservative nature of its writing system, and cultural choices made in language reform. Moreover, two other particles—「へ」 (he written, e pronounced) and 「を」 (wo written, o pronounced)—share the same peculiarity.
Old Japanese and the Transformation of h-sounds
In the Nara period (8th century), Japanese was written in man’yōgana, a system that borrowed Chinese characters purely for their sounds. At that time, the h-row consonants were not [h] as in modern Japanese but closer to [p]. For example:
- 花 (hana, “flower”) was pronounced pana.
- 春 (haru, “spring”) was pronounced paru.
Over the centuries, a sound shift occurred:
- 8th century (Nara period): [pa][pi][pu][pe][po]
- Around the 9th–10th centuries (Heian period): [fa][fi][fu][fe][fo]
- From the 11th century onward: [ha][hi][fu][he][ho]
Especially at the end of words or in weak positions, ha softened further and was pronounced closer to [wa]. This shift affected the particle 「は」, which almost always appeared at the end of a phrase.
The Special Role of the Particle 「は」
The particle 「は」 functions as a topic marker in Japanese, highlighting what the sentence is about:
- 私は学生です (Watashi wa gakusei desu, “As for me, I am a student”).
Because 「は」 was so frequent and always appeared after another word, it was particularly vulnerable to the weakening of its [ha] sound. Gradually, 「は」 was pronounced [wa], even though the written form stayed the same.
This was not an arbitrary irregularity but a natural outcome of historical sound change.
The Birth of Hiragana and the Fixing of Orthography
Hiragana emerged in the Heian period (9th–10th centuries). The character 「は」 came from the cursive form of the Chinese character 波 (ha), 「へ」 from 衣 (he), and 「を」 from 乎 (wo).
By this time, the pronunciations of 「は」「へ」「を」 as particles had already diverged from their written forms. Nevertheless, the writing system retained the old shapes. As a result, the mismatch between pronunciation and orthography became established convention.
The Edo Period and Historical Kana Usage
During the Edo period (17th–19th centuries), the discrepancy between spelling and pronunciation was already well entrenched. People spoke “wa,” “e,” and “o” in daily life, but still wrote 「は」「へ」「を」 in texts, poetry, and letters.
This illustrates how writing often preserves older forms even after spoken language changes. Orthography, in other words, is conservative.
Meiji-Era Language Reform and the Three Particles
In the late 19th century (Meiji era), Japan undertook major reforms of its writing system under the principle of phonetic spelling (表音主義). The idea was to bring spelling closer to actual pronunciation.
However, three particles were deliberately exempted from reform:
- 「は」 (wa)
- 「へ」 (e)
- 「を」 (o)
Reasons for Keeping the Old Spellings
- Clarity in writing: Particles mark sentence structure, so preserving their distinctive shapes made texts easier to read.
- Literary tradition: Works like The Tale of Genji (11th century) and countless poems used the old forms. Changing them would sever ties with cultural heritage.
- Practicality: Abruptly rewriting such common words risked confusion.
Comparison with Other Particles
The case of 「は」 is not unique. Two other particles show the same historical process:
- へ (he) → pronounced [e]
Example: 東京へ行く (Tōkyō e iku, “go to Tokyo”) - を (wo) → pronounced [o]
Example: 本を読む (Hon o yomu, “read a book”)
Together, 「は」「へ」「を」 demonstrate how the written system preserved older sounds while spoken Japanese moved forward.
Significance in Modern Japanese
For native speakers, the rule that “particles are special” is absorbed unconsciously. But for learners of Japanese, this mismatch can be confusing. Teachers often present it simply: “Only the particles は, へ, and を are read differently.”
Yet, this so-called exception is actually a visible trace of Japanese history. Every time someone says watashi wa, they are echoing a phonetic change that began more than a thousand years ago.
Final Thoughts
Why is 「は」 written as ha but pronounced as wa? The answer lies in a convergence of sound change, orthographic conservatism, and cultural continuity. Over the centuries, spoken language shifted, but the writing system preserved older habits. The same is true for 「へ (he) → e」 and 「を (wo) → o」.
This mismatch is not a mistake or quirk—it is a linguistic fossil, a cultural artifact embedded in modern Japanese. It links present-day learners and speakers to the voices of the Heian courtiers, Edo-period poets, and Meiji reformers who shaped the language.
For learners, it may be an obstacle at first. But once understood, it becomes a window into how languages evolve and how writing can serve as a record of history. The particles 「は」「へ」「を」 are not just grammatical markers; they are symbols of Japanese linguistic heritage.