What tongues were spoken in Acts chapter 2?
Speaking in tongues by definition and scriptural application is speaking the languages of men (the tongue of angels is Hebrew, please refer to the tab called "what language is the tongue of angels?").
Strong's Definition: Of uncertain affinity; the tongue ; by implication a language (specifically one naturally unacquired): - tongue
When the apostles were clothed with the Spirit, they spoke the different languages of the multitude there and every man could hear the wonderful works of Alahayim in their own language which amazed them because the apostles were Hebrew speakers from Galilee, not the respective lands of the other people.
And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.
And there appeared unto them cloven tongues like as of fire, and it sat upon each of them.
And they were all filled with the Holy Spirit, and began to speak with other tongues, as the Spirit gave them utterance.
There were twelve Apostles there and they spake other tongues that were different than their own native tongue.
And there were dwelling at Jerusalem Jews, devout men, out of every nation under heaven.
Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language.
Confirmation that tongues are languages
And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galilaeans?
And how hear we every man in our own tongue, wherein we were born?
Some of the different languages they spoke were:
Parthians, and Medes, and Elamites, and the dwellers in Mesopotamia, and in Judaea, and Cappadocia, in Pontus, and Asia, Phrygia, and Pamphylia, in Egypt, and in the parts of Libya about Cyrene, and strangers of Rome, Jews and proselytes,
Cretes and Arabians, we do hear them speak in our tongues the wonderful works of Alahayim.
The Apostles received the Holy Spirit and she gave them utterance to speak in other tongues. The scriptures showed the Apostles spake languages that the people of other tongues could understand because it was the people's own language respectively that they could hear. That is why they said "how hear we every man in our own tongue wherein we were born?"(Acts 2:8) The scripture didn't say the Spirit was on the people to hear the Apostles speak, rather the Spirit was on the Apostles to give them utterance of other tongues, so the people truly understood because it was their respective languages they were hearing from their respective areas wherein they were born being spoken by the Apostles from what the scriptures show .
Acts 2:8 And how hear we every man in our own tongue, wherein we were born?
One can affirm that the Apostles were speaking a different language by the fact that the men of Judea, who spoke Hebrew too, thought the Apostles were drunk because they couldn't understand what the Apostles were saying since it wasn't Hebrew they were hearing. Rather they heard the other languages that sounded like drunk talk to them.
Others mocking said, These men are full of new wine.
( Who were the "others" mocking?)
But Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judaea, and all ye that dwell at Jerusalem, be this known unto you, and hearken to my words:
The ones mocking were the men Judea and Jerusalem who couldn't understand them since they weren't speaking Hebrew when the Spirit gave them utterance to speak other tongues, so they thought the Apostles were drunk.
For these are not drunken, as ye suppose, seeing it is but the third hour of the day.
But this is that which was spoken by the prophet Joel;
And it shall come to pass in the last days, saith Alahayim, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams:
And on my servants and on my handmaidens I will pour out in those days of my Spirit; and they shall prophesy:
So by the scriptures, some of the different languages the Apostles spoke by the Spirit were: Parthian, Elamites (Elam/Persian), Medes (Medai), Mesopotamia (Aram), Egypt (Mizraim), Lybia (Phut), Arabian (Ishmaelites & Arabs), Asia (Magog), Phrygia (Lud), Crete (Javan), Latin (Chittim/Rome) among the other languages of the lands mentioned. (Hebrew was the native tongue of the Apostles so it was no miracle for them to speak Hebrew, the native language of the men of Judea and Jerusalem.)