The questions were put:
"Have you ever heard someone, under the influence of the Holy Ghost, speak in a language not known to them?
Do you believe that such a thing is possible?
If you have experienced this, what language did you hear?"
To which I responded:
I believe it is possible, but have never experienced or observed it. The term "gift of tongues" should not, in my opinion, be reinterpreted to include those intances where a person, such as a missionary, simply makes amazing progress in speaking a foreign language and is deemed to speak it so well that it is classified as having the "gift of tongues." The gift of tongues, as I see it, could arise in two contexts: (1) the speaker, having no knowledge of or training in a language, speaks it by pure revelation, relying only upon the Holy Ghost (and not the vocabulary they have learned) to know how to express certain things in a known foreign language; and (2) the speaker, relying only upon the Holy Ghost, speaks an angelic tongue not known to mankind, and the words spoken are universally understood as having the same meaning by both the speaker and at least one hearer. In both instances, God's purpose is to communicate something which could not be communicated in the absence of the gift. For example, it may be that angelic vocabulary has words which express ideas that cannot be adequately expressed in a known language. Or the listener needs to hear a message in their own tongue in order to understand something.
Here's what I have observed in my own life:
(1) no missionary that I've seen ever had the gift of tongues as I have defined it above, yet they have often been said to have it by people who want to redefine the term in order to inspire faith in others. In fact, one of my companions even claimed I had it, based upon a particular instance when I quoted a scripture in a foreign language. Thing was, I had already learned the vocabulary I was using, and I was simply translating the verse from how I had memorized it in English.
(2) televangelists often pretend to have the gift of tongues. They speak words that sound like complete gibberish to me and resemble some hybrid of hebrew, arabic, and farsi. The gibberish allows them and certain conspiring believers to pretend that something angelic is being said when in reality they are just feigning a miracle to get your money. It would be a rather funny exercise to separate the purported speaker in tongues and the one in the audience who claims to understand, and ask each to independently describe in English what was being said. Apart from a bunch of Hallelujahs, you'd probably find very differing accounts. As for speaking in tongues when no one understands what is being said, I can't see the point and cannot imagine what purpose God would have in mind in bringing about such an event. I seem to recall that Joseph Smith and the apostle Paul both made that same point as well.