Acts 2:4 has been part of my life for ever ..
Act 2:1 And when the day of Pentecost was fully come, they were all with one accord in one place.
Act 2:2 And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.
Act 2:3 And there appeared unto them cloven tongues like as of fire, and it sat upon each of them.
Act 2:4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
Act 2:5 And there were dwelling at Jerusalem Jews, devout men, out of every nation under heaven.
Tongues has been often faked. A big surprise for me was not finding the phrase 'heavenly language' in Scripture. Why do we simply accept tongues when the above also includes Acts 1,2, and 3? Every Pentecostal known to me including grandparents parents siblings ignore verses 12& 3.
Acts 2:4 is clearly about earthly language . It says nothing of the language of angels