Meanwhile, the moment we get tired in the waiting, God’s Spirit is right alongside helping us along. If we don’t know how or what to pray, it doesn’t matter. He does our praying in and for us, making prayer out of our wordless sighs, our aching groans. He knows us far better than we know ourselves, knows our pregnant condition, and keeps us present before God. That’s why we can be so sure that every detail in our lives of love for God is worked into something good.(Rom 8:26-28. MSG)

Praying in the Spirit can be with your heavenly prayer language or without.  Referred to in the Bible as the Gift of Tongues (1 Cor 12:10). Many Christians have had problems receiving the gift of tongues for a variety of reasons, one being that speaking in tongues makes no logical sense.  Our minds want to understand and analyze the whole process, and that will never work, faith and trust have to be in operation.  So when we know not how we should pray and the Spirit prays through us and for us, why would it not be in tongues?  Think about it, if I know not how or what to pray I need to go beyond my natural mind or thinking.  The Holy Spirit and tongues take me to that place

In Romans 8 Paul tells us how the Holy Spirit takes prayer deeper by interceding for us when we don’t know how to bring to birth the will of God for our lives, literally, the Holy Spirit is the midwife, helping us birth the future with groans and sighs.

Our minds can take us only as far as we have come—the Holy Spirit will take us further.