A few years ago an old Mexican pastor told me that the language of heaven would be Spanish… at another time a French person was said to believe that the language of heaven is French, another said Chinese, another English, another Hindi, and another German… and while in Texas I was told it would be Texan… (but only over in the Texas section of heaven).
I think the language of Paradise (Eden), or the Garden, was simply called Eden. It was what was spoken and will be spoken again in the New Heaven and the New Earth. Before the Tower of Babel there was only one language. “Now the whole earth had one language and the same words,” (Genesis 11:1). What was the “one language” everyone used? I believe it was Eden.
Perhaps speaking in tongues is merely the tip of the Edenic language that we want so desperately to be fluent in, as we get ready for the New Heaven and New Earth. I know as I speak in tongues, and as satisfying as it is, it is always like there is more language, more words and more communication yet to be. Maybe speaking in tongues is simply Eden 101.
So to answer the question, what language will we speak in Heaven: Eden.
“He who has an ear, let him hear what the Spirit says to the churches. To the one who conquers I will grant to eat of the tree of life, which is in the paradise of God (the Eden, garden) of God.” Jesus