I can think of many gairaigo noun + する verbs in Japanese, like ゴルフする, but I can think of only a handful of non-する verbs in Japanese, such as ググる (mentioned in Are there words which consist of katakana and hiragana letters together?), and they appear to be a bit slangy in nature.
Why are there very few non-する verbs in Japanese? I can think of a few hypotheses, but no way of testing them:
- There are far fewer new verbs in Japanese than there are new nouns, so most Japanese verbs were created before gairaigo was a major influence on Japanese.
- gairaigo words are somehow unsuitable for inflection, such that while they can be incorporated into the language as する verbs, as nouns don't get inflected, it's impractical to make them an inflected verb
- gairaigo words are somehow more acceptable as nouns than as verbs
I found a claim in Wikipedia that in Japanese, verbs are a "closed class", which do not easily accept new members. Elsewhere it claims that not only gairaigo but also kango contribute very few non-する verbs.
Side question: Are there fewer newly created verbs in Japanese than newly created nouns? Also, are there nouns that are mainly used as する verbs rather than by themselves?
- Are there words which consist of katakana and hiragana letters together? (not all gairaigo uses katakana, so it's possible that there may be non-する verbs that wouldn't be addressed in that question)
- Are foreign adjectives always な adjectives? (い versus non-い adjectives is reminiscent of non-する versus する verbs)