From my experience when I have gone to Catholic charasmatic services, people pray and someone is moved to go up to the front and speak to everyone in a language they are not familiar with, then someone else comes up and translates. I have seen people speak Hebrew and German. My dad used to go because he spoke many languages and he always hoped that he could translate. At our services our priest used to remind all in attendance of 1 Corinthians
27 If any speak with a tongue, let it be by two, or at the most by three, and in course, and let one interpret. 28 But if there be no interpreter, let him hold his peace in the church, and speak to himself and to God. 29 And let the prophets speak, two or three; and let the rest judge. 30 But if any thing be revealed to another sitting, let the first hold his peace.
Basically one should not speak in tongues unless there are those to interpret.
On the other hand… I went with a friend to a Vineyard service where everyone was basically speaking in gibberish… no interpretor, no one else understood what another was saying… no discernible language spoken… It just didn’t seem legitimate to me.
As a disclaimer, I am not charasmatic, nor do I regularly attend such services, I have gone to about a half dozen Catholic ones when my dad was alive, and one Protestant (if you call a non-trinitarian church like Vineyard, Protestant )