Brief Japanese - the mystery of い adjectives, or why some end with しい and other ones with just い and where their conjugations came from

Have you ever wondered why the topic particle は being pronounced as わ?Then this short text, touching the history of Japanese itself will help you understand why it is the case.

In the early history of Japanese, the modern HA row consonants (HA, HI, FU, HE, HO) were pronounced with P as PA, PI, PU, PE, PO.

So mother was pronounced as PAPA.

However, in the Nara period (710 to 794) the P sound shifted to softer F (FA, FI, FU, FE, FO).

The same phenomenon happened in Indo-European languages (Grimm’s law) for example:

Proto-Indo-European *pṓds (foot) changed to *fōt- in proto germanic languages and eventually to foot (in English), Fuß in German and Fod in Danish.

For example, mother (母(modern HAHA)was pronounced now as FAFA).We can still see remnants of this in the pronunciation of ふ (FU).In the Heian period (794 to 1185) another shift happened, the F sound changed to W, but ONLY when it followed a vowel, so it wasn’t used at the beginning of the word.

Example:母(FAFA) started to be pronounced as FAWA.川 (KAFA) started to be pronounced as KAWA. (川 - river)This sound change is the reason why the particle は is pronounced as わ, more about it a bit later.

Eventually, in the Edo period (1603 and 1867, Edo is the original name of Tokyo) when people from various areas of Japan started coming to the Edo resulting in various dialects intermixing, and the F sounds started to be pronounced as H, resulting in modern pronunciation. Of course, ふ was the exception. So 母(FAWA)shifted to modern HAHA.However, the orthography did not change and even though words were pronounced in a new way, the old kanas that represented old pronunciation were used which resulted in a linguistic wild west, luckily, most often this was the case for words written with kanji.

(By the way, another interesting sound change in the Edo period was the change of Ri to I in some words, like ござります→ございます。)

And eventually, soon after World War 2, the Japanese reformed writing, so that it would reflect the actual pronunciations so 川(かは) now was written as 川(かわ). However, the particles were excepted because many felt that changing these exceedingly common spellings would confuse readers.The same reform retained the historical writing of particles へ and を, and also 当用漢字表(とうようかんじひょう) touyou kanji list (lit. “List of kanji for general use”) were made (the precursor of modern 2136 常用漢字 (jouyoukanji).

To sum up, は is pronounced as わ because the transcript reflects obsolete now pronunciation that was not changed during the language reform.

PSThe わ used at the end of the sentence (the one used for exclamation) comes from the topic particle は, yet it is written as わ in modern Japanese.

I want use this topic to explain some Japanese grammar using a bit of etymology, so if you are interested you can observe it :slight_smile:


Long time ago, in Japanese nominals (nouns) were used as adjectives, to describe other nouns. They were simply put before modified noun.Eventually Japanese started adding し to those nouns, creating first adjectives. Some of those also gave birth to some static verbs, that’s why we have some static verbs and adjectives that sound similar.

Example: 大人 - “adult” => 大人し - “mature”

The form ending with し was 終止形(predicative form), the form only used at the end of the sentence (and not in all circumstances).

The first adjectives were the ones that represented observable physical condition.For example: 清し (‘clean’, ‘clear’).This group were called く adjectives (due to their 連用形 form)

The other group which also appeared about the same time but was less numerous (originally, since eventually, they have grown in number) also ended with し in their 終止形. They were more subjective, and described feelings and so on.For example 美し (‘lovely’)This groups were called しく adjectives (due to their 連用形 form)

While both ended with し, the major difference was in conjugation:

Conugation 清し (く adjective) 美し(しく adjective)
未然形(imperfective form (things that not happened), nai stem) - -
連用形(conjunctive form (connects), masu stem) 清く 美しく
終止形(predicative form, ending form) 清し 美し
連体形(attributive form, noun modifying form) 清き 美しき
已然形(realis form (thing that happened, used with ば and ども as in けれども) 清けれ 美しけれ
命令形(imperative form) used for orders - -

As you can see, the major difference was that in the case of しく adjectives, し stayed in all conjugations, while in く adjectives case it was replaced.Examples: なし(ない)、べし(nowadays べきだ)、ごとし,

To those conjugations various auxiliary verbs were added. Those auxiliaries were for example む、なる and some other.

You can also notice, that both kinds of adjectives did not have an imperative form or imperfective form. For that purpose verb, あり (nowadays ある) had been added to 連用形 which gave くあり ending. This was shortened to かり and conjugated for the missing forms. This gave birth to modern conjugations like past form of adjectives for example:

Conugation 清し (く adjective) 美し(しく adjective)
未然形(imperfective form (things that not happened), nai stem) 清から 美しから
連用形(conjunctive form (connects), masu stem) 清かり 美しかり
終止形(predicative form, ending form) - -
連体形(attributive form, noun modifying form) 清かる 美しかる
已然形(realis form (thing that happened, used with ば and ども as in けれども) - -
命令形(imperative form) used for orders 清かれ 美しかれ

In other words, it comes from combination of く form + ある (to exist).

くあった → かった

Eventually, い-sound change happened in attributive form, and the k in き was dropped. (Similar change happened to some verbs like ござります->ございます)


Conugation 清し (く adjective) 美し(しく adjective)
連体形 old 清き 美しき
連体形 new 清い 美しい

And this is from where we have the modern forms, eventually, the 終止形 (the predicative form) stopped being used, and the 連体形 (attributive form) took its role which made it possible to use the same form to when both modifying nouns and at the end of the sentence.

This is why some adjectives ending with しい describe feelings more often, and the ones just ending with い describe some observable phenomenonsOf course, some adjectives retained some of their original conjugations, like ごとし.You can also see sometimes なし (old predicative form) なき (old attributive form) being used instead of ない. が follows なき because attributive form could be used to nominalize in classical Japanese, just like modern の or こと.


For me, who has been entrusted as the manager of the service sector, something like days off are virtually nonexistent.