In this latter part of life, my prayer of the heart is most often without words. My tongue is stilled. My mind is stilled. The prayer of the heart becomes the heart's own respiration. I breathe in and I breathe out. It is God's breath. God breathing in, God breathing out. It is God's breath breathing me.
Even with "nothing" seems to be happening in our prayer-life, we can trust that in the Silence we are growing in contentment, serenity, understanding, empathy, friendliness and concern.