Why is "konnichi wa" written with は and not わ?


Why is "konnichi wa" in hiragana with は and not わ？




There are some lingering question marks in the initial post and in the other
answers regarding why は is read as `/wa/` in こんにちは.

Other posters have already noted that this は is the topic particle -- which is
always read as `/wa/`.

The remaining question is, **why is this particle は read as`/wa/`?**

### The short(ish) answer

The answer lies in history. According to historical linguists, all of the
modern "H" kana (and "F" kana), はひふへほ, started out as "P" kana, read as `/pa
pi pu pe po/`. Over time, this initial `/p/` sound
[lenited](https://en.wikipedia.org/wiki/Lenition) (i.e. softened) to become
more of an `/f/` sound in most places, and a `/w/` sound in some other places.
Still more recently, the `/f/` sound lenited further to `/h/` at the beginning
of a word, and in the middle of a word, it either became a `/w/` (for は) or
vanished to leave just the vowel (for ひふへほ).

_(Mid-word`/p/` sounds may be due to
[gemination](https://en.wikipedia.org/wiki/Gemination) (when a consonant sound
is doubled), or to a preceding ん. Word-initial `/p/` sounds contrastive with
`/f/` sounds appear to be a development in perhaps the 1300s-1400s, used for
imitative words and borrowings.)_

### The longer story

For the details, let's look backwards. We'll start with the Japanese of the
early [Edo period](https://en.wikipedia.org/wiki/Edo_period), when the
language was in its [Early Modern
stage](https://en.wikipedia.org/wiki/Early_Modern_Japanese). There was a very
important Japanese-Portuguese dictionary compiled in 1603, the [_Vocabulario
da Lingoa de Iapam_ , a.k.a. 日葡辞書 ( _Nippo Jisho_
)](https://en.wikipedia.org/wiki/Nippo_Jisho), which gives us a window into
the Japanese phonology (sounds) of the time. We find things like 日本 with a
reading of _Nifon_ , or 春 with a reading of _faru_ , showing that many of the
はひふへほ sounds of today were read instead with an `/f/` sound. But as a
particle, は was already `/wa/`.

Further back, even earlier during the stage called [Late Middle
Japanese](https://en.wikipedia.org/wiki/Late_Middle_Japanese) (roughly the
1100s through the 1500s), linguistic research suggests that many of the "H"
kana within a word (not at the beginning) underwent a shift, probably going
from the `/f/` we see at the beginnings of words in the early 1600s to an
even-softer `/w/` sound. From there, many of these `/w/` sounds just
disappeared -- becoming just the vowel sounds -- except for the は, which
became `/wa/`. This is possibly because of the biomechanics of Japanese
pronunciation (the shapes the mouth makes), perhaps making sound combinations
like `/wi/`, `/wu/`, `/we/`, and `/wo/` difficult, combined with a lack of any
strong need to distinguish these `/w/` sounds from the plain vowels.

_(Indeed,`/wu/` doesn't seem to have ever existed as a meaningful sound
contrast to just plain `/u/`, and `/wo/` is only very rarely encountered for を
when people are deliberately overpronouncing. Meanwhile, `/we/` apparently
became just `/e/` and `/wi/` became `/i/` some time in the 1200s.)_

We see remnants of this sound shift in modern speech. For instance, the
everyday verb 言う【いう】 "to say" has that `/w/` sound that seems to appear out of
nowhere in the negative conjugation _i **w** anai_. Historically, いう was
formerly spelled in kana as いふ, which you can still see in many Japanese-
Japanese dictionaries. This is the old kana spelling from before the spelling
reforms of the early and mid-1900s, more formally known as [historical kana
orthography
(spelling)](https://en.wikipedia.org/wiki/Historical_kana_orthography), or
[歴史的【れきしてき】仮名【かな】遣【づか】い](https://ja.wikipedia.org/wiki/%E6%AD%B4%E5%8F%B2%E7%9A%84%E4%BB%AE%E5%90%8D%E9%81%A3)
in Japanese. Starting from いふ, we find that the conjugated stems would be:

  * いふ - plain form
  * いは - incomplete stem, most often seen in the negative
  * いひ - continuative stem, often seen followed by ます
  * いへ - conditional and imperative

But in modern Japanese, the conjugated stems are:

  * いう - plain form - the "F" disappeared
  * いわ - incomplete stem - the は became わ
  * いい - continuative stem - the "H" disappeared
  * いえ - conditional and imperative - the "H" disappeared
  * いおう - volitional 

_(Side note: the modern volitional ending`/oː/` (long **ō** ) came from the
incomplete stem plus う, and the `/au/` sound (like English "ow!") evolved into
`/ɔː/` (like English "awwww") and then to `/oː/`. For volitionals where the
ending `/oː/` would start with a `/w/`, like for いふ, the `/w/` disappeared
just as it mostly has for modern を.)_

### The result: our modern Japanese particles with funny readings

Particles are treated phonologically as suffixes to some extent, so this
pattern of historical mid-word "H" kana being read with a `/w/` sound for は
also effectively applies to the particle は. Similarly, the "H" kana read as
just the vowel sound also applies to the particle へ, and that same
vanishing-"W" process that results in the `/e/` reading for へ also applies to
the particle を. The spelling reforms of the 1900s adjusted official kana
spellings to match the expected pronunciations in almost all cases -- but the
particles were apparently deemed special, and the older spellings were
maintained, even though they don't quite match the expected pronunciations:
leaving us with modern は (`/wa/`), へ (`/e/`), and を (`/o/`).

