/ideku/ → /deku/ → /dekuru/ → /dekiru/
Originally appears in the Man'yōshū of 759 CE and other Old Japanese texts as 出で来 (ideku), as a compound of 出で (ide, “going out”, the 連用形 (ren'yōkei, “continuative or stem form”) of verb 出づ idu, izu, the ancient form of modern 出る deru, “to come or go out of something”) + 来 (ku, “to come”, the ancient form of modern 来る kuru, “to come”). The original meaning was “to come out”, extending in figurative contexts to a sense of “to appear, to become manifest”.
Phonologically, ideku shifted to deku by the mid-1400s in the Muromachi period, as the low-tone initial i dropped out, vaguely similar to the way that unstressed syllables in English may disappear. This deku then underwent a common shift in Muromachi Japanese to become dekuru, where all bigrade verbs and irregular verbs underwent a shift that included a -ru on the end of the plain form, in part through a fusion of the 連体形 (rentaikei, “attributive form”) that has always ended in -ru for these verbs, and the 終止形 (shūshikei, “terminal form”) that is used at the end of sentences.
As a later part of this same shift, the central vowel shifted from -u- to -i- to produce dekiru, as the main vowel -i- for the 連用形 (ren'yōkei, “continuative or stem form”) came to be used for all conjugated forms.
Over this same period, the meaning gradually shifted from “to come out” to include “to appear, to become manifest”, and from there “to come into existence anew”. This then extended further to “to occur, to happen; to be born; to be created, to be produced”, and thence “to come to fruition; to be completed, to be finished (with positive overtones)”. The underlying sense of latent existence gave rise to the meaning of “to be capable of making or producing something”, and then simply “to be able to do”.
- Tokyo pitch accent of conjugated forms of "出来る"
|Source: Online Japanese Accent Dictionary|
|Imperative (命令形)||出来ろ||で ろ||[dèkíꜜrò]|
|Negative perfective||出来なかった||で なかった||[dèkíꜜnàkàttà]|
|Hypothetical conditional||出来れば||で れば||[dèkíꜜrèbà]|
|Japanese verb pair|
- to be able to do
- Jon wa Furansugo ga dekiru.
- John knows French.
- (literally, “John can do French.”)
- to be finished, to be ready
- 1949, 豊島与志雄, 或る作家の厄日:
- Junbi wa dekita.
- Preparations are finished. → I'm ready.
- 1949, 豊島与志雄, 或る作家の厄日:
- be made
- (slang) to have sex, to do it, to get some, to get it on
|For pronunciation and definitions of できる – see the following entry.|
|(This term, できる, is an alternative spelling of the above term.)|