Assemblies of God

The baptism of believers in the Holy Ghost is witnessed by the initial physical sign of speaking with other tongues as the Spirit of God gives them utterance.

Acts 2:4 [KJV/NIV]

The speaking in tongues in this instance is the same in essence as the gift of tongues, but is different in purpose and use.

1 Corinthians 12:4-10 [KJV/NIV]
1 Corinthians 12:28 [KJV/NIV]