One of my best friends growing up was Pentecostal and I am Baptist. I used to ask him about the "speaking in tongues" thing. He seemed to think it baloney but wouldn't say as much. I still wonder.
it's baloney.
There was a thread on this recently
I came out of a charismatic tradition and now worship at a church that is not charismatic. I will admit, it lacks a certain fire.
I studied this because I needed to make sense of it for my own Christian walk. I thought the closest author to the truth was Spiros Zodhiates, who is a greek scholar. He writes all kinds of translations and lexicons.
Basically he says the word "tongues" as used by Paul had different meanings based on whether the plural was used or not. The prayer language is not nonsense but he says it is it is self edifying and therefore not for public use. Also it holds up the church to ridicule.
I at times use a private prayer language but it is just that. It brings you into a private place with the Lord. Sort of like sweet icing on cake, it's nice but you can't live on it.