Speaking in Tongues denotes speaking various languages

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.
– 5  And there were dwelling at Jerusalem Jews, men, out of every nation under heaven.
– 6 Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language.
  –  7  And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galilaeans?
  –  8  And how hear we every man in our own tongue, wherein we were born?
  –  9  Parthians, and Medes, and Elamites, and the dwellers in Mesopotamia, and in Judaea, and Cappadocia, in Pontus, and Asia,
–  10  Phrygia, and Pamphylia, in Egypt, and in the parts of Libya about Cyrene, and strangers of Rome, Jews and proselytes,
–  11  Cretes and Arabians, we do hear them speak in our tongues the wonderful works of God.