Prayer is something deeper than words. It is present in the soul before it has been formulated in words. And it abides in the soul after the last words of prayer have passed over our lips.
It is not necessary to maintain a conversation when we are in the presence of God. We can come into His presence and rest our weary souls in quiet contemplation of Him. Our groanings, which cannot be uttered, rise to Him and tell Him better than words how dependent we are upon Him.