Even though the act of praying can be easy at times, knowing the right words to pray is difficult. Especially in moments of great pain or sorrow, sometimes we don't have the words to pray and it's comforting to read this in Jesus' Sermon on the Mount:
“This, then, is how you should pray: “‘Our Father in heaven, hallowed be your name, your kingdom come, your will be done, on earth as it is in heaven. Give us today our daily bread. And forgive us our debts, as we also have forgiven our debtors. And lead us not into temptation, but deliver us from the evil one.’ - Matthew 6:9-13
It's also really helpful to remember that even when we don't know what to pray, the Spirit of God that indwells us prays on our behalf according to God's will (Romans 8:26-27). We can rest assured that when it comes to the power of our prayers, it lies in the one hearing it, not in the one praying it.