As with all verbs, during the Middle Japanese stage in the Kamakura and Muromachi periods, the 終止形 (shūshikei, “terminal or sentence-ending form”) was gradually lost as the 連体形 (rentaikei, “attributive form”) came to be used for both the attributive and terminal grammatical roles, realigning the conjugations.
- (rare) 為る
する (transitive, irregular conjugation, rōmaji suru)
- to do
- Nani o shite imasu ka.
- What are you doing?
- to wear (accessories)
- Nekutai o suru.
- I wear a necktie.
- (に～) to make into a certain state; to cause to become
- hitori ni shinaide
- please don't leave me to be alone by myself
- heya o kirei ni suru
- to clean up one's room
- (を～) to have; to make
- kowai metsuki o suru
- to have an intimidating glare
The verb する (“to do”) is seldom written in kanji (為る).
It is common to use する after certain nouns to indicate that the noun is being done; this is highly productive, meaning many nouns can be used as verbs in this way. Some examples are:
- 勉強 (benkyō, “studying”) → 勉強する (benkyō suru, “to do studying” → “to study”)
- 旅行 (ryokō, “journey”) → 旅行する (ryokō suru, “to do journey” → “to travel”)
- (to do): 成す, 為す (nasu) (somewhat archaic, usage is more limited)
- (to do): 行う (okonau, “to carry out”)
- (used to make a verb): 〜る (-ru), a much less productive suffix for turning a noun into a verb
- す (su)
Reading for various kanji spellings.
する (rōmaji suru)
- 刷る, 摺る: to print something (from the way the paper would be placed on the printing block and rubbed)
- 掏る: to pick someone's pocket (possibly from the way a pickpocket must slide along unnoticed; compare English slick)
- 擦る, 摩る, 磨る, 擂る: to slide, to rub, to chafe, to strike (as in a match, by rubbing); to lose or waste money
- 剃る: irregular reading for 剃る (soru, “to shave”)