NET
2 For the one speaking in a tongue does not speak to people but to God, for no one understands; he is speaking mysteries by the Spirit.
Darby
2 For he that speaks with a tongue does not speak to men but to God: for no one hears; but in spirit he speaks mysteries.
KJV
2 For he that speaketh in an [unknown] tongue speaketh not unto men, but unto God: for no man understandeth [him]; howbeit in the spirit he speaketh mysteries.