Due to my meager Persian abilities, I had never heard the word “وی” (vey/vay) before. I encountered it recently while reading a grammar book, in use for the third person singular, for which I had naturally been using “او” (u). This apparently is quite formal Persian, but what’s odd is that in Kurdish switching “ew” for “wê/wî” would result in a change from the nominative to the oblique. On the other hand, subjects of Kurdish sentences are often marked by the oblique in the past tense (split ergativity), and as the past tense is closer to the infinitive than the present tense in both Persian and Kurdish, one cannot help but sense a connection.

Ew dixwe
(S)he is eating

Wî xwar
He ate

Wê xwar
She ate

وی میخورد
Vey mixôrad
(S)he is eating

وی خورد
Vey xôrd
(S)he ate

So the present stem in Kurdish is “xw”, the past is “xwar”, which is close to the PRESENT stem in Persian “xôr”, but the past stem in Persian is “xôrd” (“I ate”=من خوردم/man xôrdam). In both cases the past stem is more complex (and we must assume conservative) than the present stem. The fact that Kurdish uses the oblique to mark the subject with the past tense’s more conservative form of the verb while Persian appears to have replaced the nominative with the oblique in all cases implies that the oblique’s dominance in Iranian languages is quite an old phenomenon. Consulting Geoffrey Haig’s book on the subject, it appears that indeed the Persian personal pronouns of today are derived from older Persian obliques (although Kurdish “tu” looks like Persian “tô”, in Older forms of Persian a high rounded vowel in that word implied the nominative while a low rounded vowel implied the oblique, could Kurdish have gone through an intermediary stage where the nominative was “tu” and the oblique was something like “tö”?). Persian’s “man” is certainly closer to Kurdish “min” than “ez”, and indeed Old Persian first person singular nominative was “adam”. But this “vay/vey/u” is still vexing. Although this general trend of shifting the oblique to the nominative confirms “vay” and “vey”s relationship to the Kurdish oblique forms “wê/wî”, whence “u”? Because it is such a simple form, there are three (similar) explanations which immediately spring to mind:

  1. If you look at the third person plural pronoun in Persian “ånhå” it is obviously just “ån” (that) pluralised regularly. Similarly, in Kurdish all third persons (regardless of gender or number) in the nominative are indicated with “ew” (that), and in the oblique this is merely declined for gender or number (“wî”, “wê” and “wan”, respectively, incidentally if one wishes to use “this” in any of those four forms, one merely has to replace “w” with “v”). The various forms of the third person in most Iranian varieties are simple enough that it’s possible to imagine that one of them came out as “u”, which ousted the old oblique due to its ability to act both as a pronoun and a modifier (“u mard”, that man).
  2. Modern Persian lacks gender, but Persian used to have gender (as Kurdish still does). Among the factors likely to have resulted in Persian’s loss of gender was the fact that at a certain point in the history of the language, the palaces responsible for maintaining the elite forms of the language were filled with Georgians and Turks whose mother tongues lack grammatical gender (and in neither is there a distinction between “he” and “she”). Furthermore, the third person singular pronoun AND the word for “that” (as modifier or pronoun) in Oğuz Turkic is universally “o”, which takes five seconds to learn how to use properly and is very useful. This could possibly have been borrowed into Persian at some point and then raised to a high vowel.
  3. Both the above factors combined to simplify an earlier form of the Persian third person (perhaps “vay/vey” itself, the “v” was not always “v”, as Kurdish implies and as Afghanistani pronunciation confirms) into “u”. This would not be unlike the apparent situation with “ki” among Turks (in reverse), whereby Kıpçaks have a “k+high vowel” suffix which harmonises as any other high vowel suffix would, which is also attested in Orkhon inscriptions, but in Turkey today there are only two forms, both front, under the influence of Persian “كه”.