There seems to be TWO types of tongues.
One; a language man CAN translate into a language that is spoken somewhere on earth.
Two; a language that only GOD can understand.
1. Acts 2:5-11
Now there were staying in Jerusalem God-fearing Jews from every nation under heaven. When they heard this sound, a crowd came together in bewilderment, because each one heard their own language being spoken. Utterly amazed, they asked: “Aren’t all these who are speaking Galileans? Then how is it that each of us hears them in our native language? Parthians, Medes and Elamites; residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, Phrygia and Pamphylia, Egypt and the parts of Libya near Cyrene; visitors from Rome (both Jews and converts to Judaism); Cretans and Arabs—we hear them declaring the wonders of God in our own tongues!”
2. 1 Corinthians 14:2
For anyone who speaks in a tongue does not speak to people but to God. Indeed, no one understands them; they utter mysteries by the Spirit.
Interesting.
I always presumed that the verse about speaking to God meant that if there was no one around to interpret, like if I spoke the Dani language around someone who didn’t know it, then only god would or could understand it. But that it was still a human language.