Clauson (1972)
An etimological dictionary of pre-thirteenth-century Turkish
p. 223
D erki:
an Adv. discussed in v. G. ATG para. 359 and Hüen-ts. Biog., p. 21, note 62; in spite of the contrary opinion expressed therein, it seems, except on the rarest possible occasions, to be used only at the end of questions to indicate that a categorical answer is not expected; the best translation is, therefore, a periphrasis like ‘do you suppose that . . .’ or ‘is it likely that . . .’. Like erken and 1 erinç it seems to be a Dev. form fr. 1 er- dating back to a time when the verbal Suffs. were rather different fr. those in viii and later. Survives only(?) in NE Tuv. irgi ‘a particle used in questions to make them more polite’. Uyğ. viii ff. Man. amtı ertip kalır erki sen ‘now you are perhaps passing away?’ TT II 15, 7-8: Bud. bola:r (sic) yeg mü erki a:zu erme:z mü erki tep seziklig bolmış ‘having become uncertain whether these things were good or perhaps not’ TT VIII H.5-6; alı çevişi neteğ erki ‘what sort of devices (Hend.) do you suppose that he uses?’ U II 16, 24; Kuan. 99-100; ne tıltağın ne üçün teginmek bolur erki ‘for what reason and why do you suppose that perception (Sanskrit vedana) occurs?’ U II 10, 17-18; o.o. of direct questions U II 22, 4; 31, 43; U III 45, 6; U IV 14, 145-6; Suv. 132, 15; 599, 23; Hüen-ts. 62(?), 1829, 1884, etc.—tıŋlağalı bolğay erki men ‘I shall, I suppose, listen’ U III 29, 4-5: Xak. xi erki: ḥarf şakk ‘a particle expressing doubt’; hence one says ol kelir mü erki: a yaḥḍuru huwa am lā ‘do you suppose he is coming or not?’; wa huwa yanūbu manāba’l-istifhām it takes the place of an interrogative Kaş. I 129: KB nelük tuğdum erki yana ölgeli ‘why do you suppose that I was born, if I am just to die?’ 1136; kavuşğum kaçan erki teŋri bilir ‘God knows when, if ever, we shall meet again’ 6176; a.o. 5121 (2 öt): xiii(?) Tef. erki in questions and statements ‘perhaps’ 82: Çağ. xv ff. see erken: Xwar. xiv erki in questions Qutb 21.