Prayer, song, praise, and thanksgiving are presented to God personally and congregationally. Prayer is often defined as a formal request, a petition, and simply communion with God. A prayer can be written by someone else. For example, we pray the Lord’s Prayer as recorded by the gospel writers. (Luke 11:2-4) We also pray with our mind and heart, as Jesus did during the Last Supper (John 17).
A song has melody and meter. Praise may or may not have melody and meter. Jesus and the apostles sang a traditional Jewish hymn during the Last Supper (Matthew 26:30; Mark 14:26). Thanksgiving is gratitude expressed exclusively to God.
Prayer, song, praise, and thanksgiving can be given from our mind with understandable words through our physical tongue, and from our spirit with unperceivable words through the same physical tongue (13-14). Apostle Paul tells the Corinthian congregation when it is proper to use each. When we are before the congregation, we should edify the mind with perceivable language. The minds of all present should understand what is said. When we are alone, we can pray in a tongue even though our mind does not understand (15-17).
Apostle Paul spoke tongues in private and thanked God for it. I have too. When you are alone and want to praise and thank God, but have no words or lack perceivable language to express your thankfulness and praise, rather than ramble on with repetitive words as the pagans (Matthew 6:7-8), pray and/or sing your praise and thanksgiving with your spirit by the use of tongues if you have that gift. God looks at the heart and sees your offering that comes from the spirit and accepts it.

