onelamb is correct. there are actually 4 types of tongues in this gift. not all of us will ever flow in all of these either. the first is tongues for personal edification, this is your personal prayer language with God. this will helpto build you up, and also help to fulfill God's perfect plan for your life. after all, it's the Holy Spirit praying through you, and who was with God when He ceated you before the foundations of the world? the next is togues for interpretation, God will give someone in the congregation (or prayer meeting) utterance, which will be followed by the interpretation, either from that person, or another in the group. the next is sometimes refered to as tongues as a sign to the unbeliever, sometimes you will just have an "urge" to pray in tongues, sometimes while preaching, sometimes all by yourself in a group of strangers, whatever the case. anyway, God will actually be speaking through you to someone else in a laguage that is foriegn to you. This is awesome when it happens! It has never happened to me, but I know of several times that it has happened. the last one is intercessary prayer. this is standing in the gap for a fellow christian. sometimes those who are built up in their prayer language have this need to pray come over them. if they submit, and begin to pray, they are actually praying for someone in the body of Christ who is in trouble somewhere in the world. Some are called to be intercessors, others will only do it a few times in our lives, if at all. God will use each and every one of us if we allow Him to do so.