No Judy, that's incorrect~unknown tongues in the scriptures is without exception a known language somewhere in this world~it would be nice to think otherwise for a few reasons, mainly, NO ONE COULD could verify what you were saying.
I will give a Few
Ideassober words from the Apostles concerning unknown tongues....later. Is it not strange that our Lord never worship God in that manner, but did worship God when considering certain Bible truth, mainly God's sovereignty in revealing the truth to some and hiding truths from others, which all Pentecostals hates the thoughts of! Selah.
I dont need anyone to verify what God gives me to pray because I trust Him. I know thats its always in His will. There have been many examples where someone who was praying in tongues was told what language it was by someone from that country who was there. In my last church a message was given in tongues, that a visitor told him afterwards was a message to her church in her own language. He was amazed as he had no idea that he was speaking in that language, and had never been to her country.