Erdal (2004)
A Grammar of Old Turkic
p. 252
yorï- 'to walk' denotes ongoing action when used as an auxiliary, e.g.: kamag on bölök šastr yaratdi; amtï barča keŋürü yorïyur (Ht V 1 b 5) 'He composed a śāstra of all in all ten chapters; at present he is busy elaborating on it all'; anta ymä sansiz tümän suvdakï tïnlïglar buza butarlayu yoriyurlar sorarlar tikärlär sančarlar (Maitr 183v24) 'There, again, innumerable myriads of water creatures are busy destroying them and tearing them to pieces and they suck them out, sting them and pierce them'. The use of yorï- as auxiliary has to be distinguished not only from the meaning 'to walk' but also from the meaning 'to live' or 'to lead a certain way of life' and from its use as copula (section 3.29). The instance tamudin kurtulup amtï bo käntü uvut yenlärin äŋinlärintä yüdä örtänü yala yorïyurlar (Maitr 75v20), e.g., could have the verb yorï- either as auxiliary or in the more literal meaning of 'walking about carrying their penises on their back' or just 'living with their ... loaded on their back'. kayusï muŋadu adïnu oynayu külä yoriyurlar (Maitr 89r17) could also describe the gods' way of life and not just their current behaviour, although the sentence is an utterance by somebody who just happens to meet them: He might be extrapolating from his observation. The difference between är- and yorï- as auxiliaries with the vowel converb may be that the activity is current with är-, a way of life with yorï-. A further instance governing the aorist of the lexical verb is quoted above in this section. Usually, yorï- governs the vowel converb, this actional phrase leading to the present form in the Oguz languages.