John 14:16 - Jesus Promises the Holy Spirit before he departs... "If you love Me, you will keep My commandment" .... "Love one another as I have loved you", and I will ask the Father, and He will give you another Advocate to be with you forever.
Acts 2:2-4 says, “And suddenly a sound came from heaven like the rush of a mighty wind, and it filled all the house where they were sitting. And there appeared to them tongues as of fire distributed and resting on each one of them and they were all filled with the Holy Spirit and began to speak as the Spirit gave them utterance.” It was the Day of Pentecost
Here they were all speaking in the language known to them,(Not unknown) and they that heard them understood the message and continued the conversation in the language they knew and all understood each other well. Have you wondered how the animals on land, and birds in the air communicate. Do they proclaim in Tongues or is it just a higher level of communication we are unaware of.