1. There are three types of speaking in tongues. Each type has a different purpose. Everyone can experience the first and second type - the initial evidence of receiving the Holy Ghost and tongues used in personal prayer. Some people may never experience the third type of tongues (the Spiritual Gift); although, it is something to which we should definitely aspire.
2. The following diagram illustrates the three types of speaking in tongues with scriptures that apply to each:
INITIAL EVIDENCE TONGUES TO BE TONGUES TO BE
SCRIPTURE HOLY GHOST PRAYER SERVICES ONLY
by Roger W. Skluzacek, copyright October 29, 2007