However, earliest Christianity has always defined prayer as conversation, as in conversation with God. Conversation, as any other act of communication ( e.g., talking, conversation, yelling, etc.), requires a sign of the direction of the communication: one talks to someone, communicates with someone, prays to someone, converses with someone, yells at someone, etc. Hence, praying to God, a Saint, the Virgin Mary indicates simply the direction of prayer communication. It is more a matter of grammar and understanding communication than acknowledging the worship of the receiver.
From the earliest of Church Councils the distinction was made between worship and honor. Catholics believe that worship is due to God alone. Catholics honor those saints who have gone before us as a sign of faith and victory in living the Christian life. So no, we do not pray TO saints or Mary, but WITH the saints in heaven and WITH Mary, the Mother of God. We also pray directly TO God, our Father.
As I said in an earlier post, Protestant Christians have a misunderstanding about Catholic Christians. One Catholic writer explained that Catholics believe that there is a hierarchy, or order, of Christian truths. I would like to take the liberty of quoting from the book Catholic and Christian because it helps non-Catholic Christians understand a bit better about Catholic beliefs.
Practically speaking, this (the hierarchy of truths) means that the beliefs that are most important to Catholics are truths such as the divinity of Jesus, the necessity of his death on the cross for our salvation, the reality and power of the Holy Spirit, and so on. Here Catholics find common ground of understanding and cooperation with other Christians, because Catholics and most other Christians usually agree on the most central and basic doctrines of Christianity. However, Catholics believe that there are othe Christian truths, such as those concerning Mary, the saints, purgatory, and so on, that are indeed true, but not central points of the Gospel message. It is important for both Catholics and other Christians to recognize this distinction. Sometimes Catholics are guilty of viewing and talking about Mary, the saints, purgatory, and similar beliefs as if they were the most important Christian truths. This often produces an unnecessary obstacle to unity with other Christians. ... On the other hand, sometimes other Christians focus unduly on Catholic beliefs about Mary, the sints, purgatory, indulgences, and the like (often rejecting them in a one-sided way, even when they have some basis in the Bible) in order to portray Catholics as "un-Christian", or to accuse the Catholic church of distorting the Gospel of Jesus Christ.
What I think this means is that Catholics and other Christians agree on the main tenets of Christianity. We believe that the Bible is the inspired Word of God; that Jesus died for our sins and our salvation; that he rose from the dead and is seated at the right hand of our Father; and that he will come again in Glory to judge the living and the dead. Catholics and other Christians believe in the Holy Trinity, that God is One in Three (Father, Son and Holy Spirit). I think that this is a good basis for discussion, provided that we debate as brothers and sisters, and not as enemies.
God bless.