Qun:

"This suffix is used only with plural subjects."

lieven:

Dach wa' ja'chuqwI'

jIyajbe'; reH cha' SeSor ghajnISchugh {-chuq}, vaj chay' wa' nuv neH
boplaH {ja'chuqwI'} ?

ja'chuqwI' isn't a verb, it's a noun. A noun does not have subjects. You have to think of it this way: if it were a verb, it would have a plural subject, but it's been turned into a noun, so those plural subjects are only conceptual.

One would be perfectly justified in declaring a word like this iffy and complex and in deciding not to use it. But it seems quite sensible to me.

-- 
SuStel
http://trimboli.name