Will the inhabitants of Paradise speak Arabic? If this is a fact, what is the evidence from the Quran and the Sunnah?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

We did not find any prophetic statement that addresses the language of the inhabitants of Paradise and whether it is Arabic or not.

The available quotes in this regard are attributed to the companions and those who succeeded them. For instance, commenting on the verse in which Allaah Says (what means): {In a clear Arabic language.} [Quran 26:195] Ibn Katheer mentioned that Ibn Abi Haatim stated that those who enter Paradise will speak Arabic.

Ibn Al-Qayyim mentioned on the authority of Ibn ‘Abbaas that the language of the people of Paradise is Arabic. Az-Zuhri adopted the same opinion.  

Allaah Knows best.