"to another divers kinds of tongues" (1 Cor 12:10) In my opinion, this gift is the most commonly misunderstood gift among the nine gifts. Most people understand that someone speaks in tongues when they are baptised with the Holy Spirit; but not everybody understands the ability of someone to speak in many tongues as a gift from the Holy Spirit. But for the purpose of this lesson, I will carefully avoid stepping into the need to differentiate the two by simply saying that the former is a "sign" while the latter is a "gift". It must be understood that the word "tongue" here refers to language. The most important thing about speaking in tongues is that it is as the Spirit gives uterrance; and just like every other gift, it operates by faith. Speaking in tongue is not gibberish as was shown by the events of Acts 2. And even in our modern time, there has been instances of people whose tongues were instantly recognised as an actual language by someone who heard it. One thing is fundamental about speaking in tongues, and that is the person speaking the language does not know it; and has never learnt it. He or she is supernaturally moved by the Holy Spirit to speak. That is why it is sometimes called speaking in an unknown tongue. .
To put it frankly, speaking in tongues is supernatural utterance by the Holy Spirit in languages never learned by the speaker, and in most cases never understood by the hearer. It has nothing to do with the linguistic ability nor with the mind or intellect of man. It is all about the power of God. Many people who doubt the authenticity of this gift do so because they insist that nobody understands the language that is being spoken; and so it must be something the speaker made up. Some people even go as far as using some high sounding homophonic words (such as suzuki nawasaki, orobo scatter etc) to mimic this gift. But I think God purposely uses a completely strange language in order to protect the authenticity of this gift. Look at what the Bible says:
"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 spaketh mysteries" (1 Cor 14:2).
Speaking in tongue is for exhortation and edification and comforting; and unless it is followed by an interpretation; it is purely a self-directed gift. Through this gift the user edifies himself and talks to God.