The following verses from the Acts of the Apostles associate the coming of the Holy Spirit upon the apostles and their reception of a particular gift of "speaking in tongues." The apostles were astounded by this gift as it was discovered that even though the place was filled with a wide variety of people who spoke different languages, everyone heard and understood what was being said.
When the day of Pentecost had come, they were all together in one place. And suddenly a sound came from heaven like the rush of a mighty wind, and it filled all the house where they were sitting. And there appeared to them tongues as of fire, distributed and resting on each one of them. And they were all filled with the Holy Spirit and began to speak in other tongues, as the Spirit gave them utterance.
Ever since then certain Christians have experienced a similar phenomenon and claim to have received the "gift of tongues," able to interpret and speak languages that were foreign to them.
The Catechism of the Catholic Church speaks of this type of miraculous gift as a special "charism."
There are furthermore special graces, also called charisms after the Greek term used by St. Paul and meaning "favor," "gratuitous gift," "benefit." Whatever their character -- sometimes it is extraordinary, such as the gift of miracles or of tongues -- charisms are oriented toward sanctifying grace and are intended for the common good of the Church. They are at the service of charity which builds up the Church.
The Catholic Encyclopedia explains, "In post-Biblical times St. Irenæus tells us that 'many' of his contemporaries were heard 'speaking through the Spirit in all kinds (pantodapais) of tongues' ... St. Francis Xavier is said to have preached in tongues unknown to him and St. Vincent Ferrer while using his native tongue was understood in others."
The gift of tongues is exactly that, a special gift given by God for a specific purpose in building up the kingdom of God.
Recently this special charism has become a feature of various Catholic and Christian groups. The Catholic Charismatic Movement has much to say about this particular gift and how it is utilized by the Church.
As with all the gifts of the Spirit, these graces (or charisms), as St. Thomas Aquinas taught, are for evangelization – the sharing of the faith.
This is obvious in the case of speaking in tongues (as opposed to praying in tongues); for example, one friend at university was enabled by the Holy Spirit to speak to a group of French students, even though he knew no French. He was not only able to help them but also to share his faith with these young people.
I've also heard of a man who went to a synagogue and started praying along in tongues and heard later from his neighbour in the service that he had been praying fluently in Hebrew.
As noted here, "speaking in tongues" is not to be confused with "praying in tongues," which is understood to be something much different and can often seem like a string of unidentifiable utterances.
Relatively very few people are granted the charism of speaking in tongues, as God grants various kinds of gifts to each person, not seeking uniformity, but diversity. St. Paul explains this in his letter to the Corinthians.
Now there are varieties of gifts, but the same Spirit; and there are varieties of service, but the same Lord; and there are varieties of working, but it is the same God who inspires them all in every one. To each is given the manifestation of the Spirit for the common good. To one is given through the Spirit the utterance of wisdom, and to another the utterance of knowledge according to the same Spirit, to another faith by the same Spirit, to another gifts of healing by the one Spirit, to another the working of miracles, to another prophecy, to another the ability to distinguish between spirits, to another various kinds of tongues, to another the interpretation of tongues. All these are inspired by one and the same Spirit, who apportions to each one individually as he wills.
It is a gift from God, one that is directed toward a purpose and must be received with an open heart.
