Why are there non-Arabic words in Quran?

Answer

In the name of Allah, if your intention is to object to the One Who says the words, I advise you to repent to Allah, before the bad consequences of such an act happen to you in this world before the hereafter. On the other hand, if you mean that language of Quran is not Arabic, a consensus agreement that Quran is revealed in Arabic, especially the proper nouns in it and so do the other types of nouns, as their rules are the same as those of the proper nouns. Additionally, Quran does not contain non- Arabic derivations. Allah is the all Guide and Knowing.