You can find a bit of a study on the gifts of the Spirit
Here (including the gift of tongues),
This study will also be helpful...
Was baptised in the Holy Spirit 30 years ago, with the evidence of speaking in tongues, it is the most important of the 9 gifts of the Spirit, as when used regularly in the personal prayer life of the believer (1 hour + per day), it puts love into the soul and is the gateway to the operation of the other 8 gifts of the Holy Spirit, Paul thought
VERY highly of it and used it continually, indeed it was the reason for his great ministry! Matt 6v6, Mark 16v17, Acts 2v4, 10v44,46, 11v17, 19v1-16, Rom 8v26, 15v18-21, 1Cor 12v7-11, 1Cor 14v4,18, 2Cor 12v11,12, Eph 1v13 (KJV), Jude v20,21
Yahweh Shalom...