What are the essential forms of prayer?

The basic forms of prayer: blessing, adoration, petition, atonement,  reparation,love,intercession.thanksgiving and praise.

Blessings come to us by the grace of the Holy Spirit that descends through Christ from the Father. Because God blesses the human heart, it can return, (praise and adore) him who is the source of every blessing. Through blessing, our prayer ascends in the Holy Spirit through Christ to the Father.

Through adoration, we exult the greatness of the Lord who made us and the Almighty power of the Saviour who sets us free from evil. It is a respectful silence in the presence of the "ever great" God.

By prayers of petition we express awareness of our relationship with God. We are creatures ever in need God.We are sinners who have turned away from our Father. Our petition is already a turn back to him. The first movement of the prayer of petition is to ask for forgiveness: "God be merciful to me a sinner!" It is a prerequisite for righteous and pure prayer. A trusting humility brings us back communion with God and our neighbor, so that we receive from God whatever we ask.

In a prayer of expiation or contrition, we acknowledge our sinfulness and ask God for his forgiveness and mercy. The Confiteor or Penitential Rite at the beginning of  Mass, and the Agnus Dei (or Lamb of God) before Communion, are prayers of expiation, as in the Act of Contrition.

A prayer of reparation is one that aims to repair the sins of others and the outrages and many offenses and sacrilages committed against the Holy Trinity and the Immaculate Heart of Mary . A "Holy Hour of Reparation" before the Blessed Sacrament and the five first Saturdays devotion" is an example of this form of prayer/devotion.

Prayers of love or charity are expressions of our love for God, the source and object of of all love. The act of charity is perhaps the best example of a prayer of love.

Prayer of intercession consists in asking on behalf of another. In intercession , he who prays looks "not only to his own interests, but also to the interests of others," even to the point of praying for those who do him harm. The intercession of Christians recognizes no boundaries: for all men , for Kings and all who are in high positions, for persecutors and for the salvation of those who reject the Gospel.

Thanksgiving characterizes the prayer of the Church. Every joy and suffering, every event and need can become the matter for thanksgiving which, sharing in that of Christ, should fill one's life: "Give thanks in all circumstances" (1 Thess 5:18).

Praise is the form of prayer which recognizes most immediately that God is God.

It lauds God for his own sake and gives him glory, quite beyond what he does, but simply because HE IS. By praise, the Spirit is joined to our spirits to bear witness that we are children of God. Praise embraces the other forms of prayer and carries them towards God. The Eucharist contains and expresses all forms of prayer: it is "the pure offering" of the whole Body of Christ, it is the sacrifice of praise."

[ See CCC 2623-2649]