Acts 2 NIV
The Holy Spirit Comes at Pentecost
1When the day of Pentecost came, they were all together in one place.
2Suddenly a sound like the blowing of a violent wind came from heaven and filled the whole house where they were sitting.
3They saw what seemed to be tongues of fire that separated and came to rest on each of them.
4All of them were filled with the Holy Spirit and began to speak in other tongues
a as the Spirit enabled them.
5Now there were staying in Jerusalem God-fearing Jews from every nation under heaven.
6When they heard this sound, a crowd came together in bewilderment, because each one heard their own language being spoken. 7Utterly amazed, they asked: “Aren’t all these who are speaking Galileans? 8Then how is it that each of us hears them in our native language? 9Parthians, Medes and Elamites; residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia,b 10Phrygia and Pamphylia, Egypt and the parts of Libya near Cyrene; visitors from Rome 11(both Jews and converts to Judaism); Cretans and Arabs—we hear them declaring the wonders of God in our own tongues!” 12Amazed and perplexed, they asked one another, “What does this mean?”
13Some, however, made fun of them and said, “They have had too much wine.”
Peter Addresses the Crowd
14Then Peter stood up with the Eleven, raised his voice and addressed the crowd: “Fellow Jews and all of you who live in Jerusalem, let me explain this to you; listen carefully to what I say.
15These people are not drunk, as you suppose. It’s only nine in the morning!
As you can see in Acts 2:6-11, it clearly says that they are speaking in actual foreign languages. There was someone that once speculated that everyone knew Greek at the time and the different Greek dialects per region were so different that they were different languages and that is what they were speaking. Regardless, they were speaking in different languages understood by peoples from all of the different regions shown in Acts chapter 2. Acts 2:13 is kind of funny, I haven't had any alcoholic beverages for years but when I did, I never spoke perfectly in a language that I didn't know. Then Peter's response is also strange in Acts 2:16 as they can't be drunk since it's nine in the morning. I know some alcoholics that grab for a bottle right when they wake up. Not a very good argument.