"Ma tinsistish", "ma texistish", the President of the Republic repeated, exclaiming: "What is this language?! It's not French, nor Arabic, nor Tamazight." Looking irritated, he added "I've heard some say that this is a matter of Algerian specificities. If so, I refuse as a citizen to be a part of these specificities."Silly as it may sound, this borrowing does have advantages. kayen is the usual way of expressing "there is" in Algerian Arabic, but there are contexts in which it simply won't work - you could not reasonably render "I exist" as *kayen ana, or "Homer existed" as kan kayen Homer (any more than "there's me" or "there used to be Homer" really mean the same thing.) You have to have recourse to loanwords for that, whether you use a Classical Arabic word (mawjuud, say) or a French verb.
(L'Expression 9 Mar 2006. The quote can't be found on the official record, which just has a general condemnation of the "repulsive jargon we use in our daily dealings, in which it's sometimes hard to find our national language or even our original unadulterated colloquial dialect.")
Anyway, I did a quick web search for examples of this, not expecting much - but it seems that the online corpus of colloquial Algerian Arabic is bigger than you might have thought, and as full of code-switching as you might expect given who is most likely to have web access. Anyway, presidential proscription or not, a number of examples come up:
* hahahaha mazal yexisti had nou3 taa les femmes? (lol does this kind of women still exist?)
* Antik yerhem waldik, can u send me the link of derja dikssiounaire blenglizia ila yexisti bien sour (Antik please can u send me the link of Darja Dictionary in English if it exists of course)
* Hiphop ma zal yexisti (Hiphop still exists)
* en deux mots : ma yexistich en un mot makachou. (In two words: it doesn't exist. In one word: there isn't any.)
* c un ideal li ma yexistich (It's an ideal that doesn't exist)
Note the -i in this verb. In Algerian Arabic, Classical final-y verbs have mostly merged to end in -a in the past 3rd person and -i everywhere else: bka "he cried", yebki "he cries", bkit "I cried", ebki "cry!"; wella "he returned", ywelli "he returns", wellit "I returned", welli "return!". The rest of the stem remains constant throughout the conjugation; only the final vowel changes in such cases. Some of the commonest forms of French verbs happen to end in [e]: j'existais, il existait, exister, existez... So by an interesting compromise, throughout North Africa most French verbs are borrowed as final-y forms: tilifuna "he called", ytilifuni "he calls", tilifunit "I called", tilifuni "call!" (< telephoner). exister is no exception.
I wonder if other dialects have adopted this word too? I found one example from Tunisia, but that scarcely counts as a different dialect...