On jisho.org, words like ''達する'' are marked as ''Suru verb - special class''. What is this so called ''special verb class?''


2 Answers 2


I think they are special because they have different conjugations from normal する-verbs, for example...

Regular する-verbs conjugate like...

勉強する → 勉強できる(potential) 勉強しよう(volitional) 勉強しない(negative)
理解する → 理解できる(potential) 理解しよう(volitional) 理解しない(negative)

The "special" する-verbs (i.e. verbs with ~す variants), conjugate like...

達する → 達せられる/?達せる(potential) 達しよう(volitional) 達しない/達さない(negative)
愛する → 愛せる(potential) 愛そう(volitional) 愛さない(negative)
訳する → 訳せる(potential) 訳そう(volitional) 訳さない(negative)


  • ムズい・・・ 達する、愛する、訳する、察する、は special verbs で、達す、愛す、訳す、察す、禁じる、は godan/ichidan だって~ ふえええ
    – chocolate
    Commented Jan 29, 2018 at 5:22
  • 「 適する」と「適す」は同じ単語だと思う?
    – jarmanso7
    Commented May 17, 2020 at 15:04
  • "The "special" する-verbs conjugate like... "って、実際に "suru verbs"についてじゃなくて、す五段動詞についてではないだろうか。少し分かりにくいんだけど。
    – jarmanso7
    Commented May 17, 2020 at 15:09
  • 1
    「適する」vs「適す」は、意味は同じですけど、形も活用も異なるので、「同じ単語」とは言えないと思います。ここでブロッコリさんが書いている、 "variants" と呼ぶべきでしょうか。
    – chocolate
    Commented May 18, 2020 at 1:26
  • 1
    – chocolate
    Commented May 18, 2020 at 1:51

From Wikipedia:

These are single kanji suru forms. ‘While 〜する suru verbs following a two-kanji compound are regular (using the admittedly irregular conjugation of suru), behaving as a kanji noun followed by an independent verb, there is irregular behavior for single kanji suru verbs, and they behave as a single fused word, with various forms and sometimes irregular conjugation. ‘

Below are some examples of single-kanji ‘special’ forms, compound forms, and regular verb forms. Note that meaning/nuance can change between the different forms:

Single - Double - Regular form

旅する - 旅行する - X

反する - 対抗する - 反る

与する -  供与 - 与える

休する - 休憩する - 休む

生ずる - 生起する - 生きる

禁ずる - 禁止する - X

要する - 要求する - 要る

In Japanese, these are called サ行変格活用 (irregular conjugation suru-form verbs).

There are pages of examples of these verbs and their meanings that can be found here.

  • I came across this "special suru verbs" doubt myself during my studies, and I found this Q&A entry. I am trying to understand the topic. This answer looks coherent to me, but I'm hesitating to trust it since it's downvoted... any thoughts on why it might be incorrect? Thank you.
    – jarmanso7
    Commented May 17, 2020 at 14:58
  • Aren't you mixing transitive and intransitive verbs here? For example, the meaning of 反する is 'to return something' (transitive), whereas 返る is 'to return' (intransitive). The transitive would be 返す.
    – kandyman
    Commented Jun 16, 2020 at 12:52

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