Praying in tongues is a spiritual gift recognized through the Holy Spirit. It is full of mysteries and it's not related to any human language. When people gives their life to Christ, it will be clear that the holy spirit is present and one of the evidence is praying in tongues.It is not about singing praises and worship.It is a form communicating with the Holy Spirit. Acts chapter 2 verses 7 and 8, they prayed in tongues and people from various places recognized their own languages.Anybody can be given this gift. Praying in tongues strengthens our relationship with God especially when answers take time.Some people practice praying in tongues without proper understanding and forget that it's understood only by God.
Even though it is not a must to speak in tongues, but I strongly believe it will goes a long way to to help our Christian walk if we speak in tongues