Sometimes we do not know what to pray for. We know how to pray, and we know what name to pray in, but we don't always know what we should pray for, and that is were the Holy Spirit comes to our aid. Rom 8:26.. Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered. Ever hear of a guy named "P. C. Nelson? He was a Greek scholar who is the founder of the "Southwestern Bible Institute", he said the Greek word in Romans 8:26 literally reads, "...the Holy Ghost maketh intercession for us in groaning that cannot be uttered in articulate speech" Articulate means, "in your normal regular kind of speech" I have never heard anyone groan without some kind of noise, have you? If there is no noise then there in no groaning. Besides, the Holy Spirit does not pray for us, he only helps us pray, that is why he is called our helper. Also Paul said, "For if I pray in an unknown tongue, my spirit prayeth...." The Amplified Bible says.... 1 Co 14:14.. For if I pray in an [unknown] tongue, my spirit [by the Holy Spirit within me] prays, but my mind is unproductive [it bears no fruit and helps nobody].