Why is God addressed with 'tu' in French but the Virgin Mary with 'vous'?

Why is God addressed with ‘tu’ in the "Our Father’(Notre Père) in French but the Virgin Mary with ‘vous’ in the ‘Hail Mary’’( ‘Je Vous Salue Marie’)? In English both are addressed with thee and thou (the familiar ‘you’).

From what my father told me, in the 1940s, the Notre Père did use the polite form when recited in French : “Notre Père qui êtes aux cieux, que Votre nom soit sanctifié, …” ). However, this prayer was part of the liturgy and so was recited in Latin during mass.

The Vatican II Council in the 1960s chose to abandon Latin for vernacular language. Apparently, the Latin words translated into “tu”, so the French liturgical texts were written to address God and the saints in the familiar form. The prayer thus became “Notre Père qui es aux cieux, que ton nom soit sanctifié…” at that point.

But the Ave wasn’t actually part of the liturgy, and continued to use the polite form : “Je vous salue Marie…”

(Source)

Thanks Heracles. I wasn’t aware that the ‘Ave’ wasn’t part of the liturgy.

I don’t know about French, but in Middle English and early modern English, “thou” vs. “you” is an art and not a science. For example, Chaucer’s poem “An ABC,” which is a lengthy acrostic prayer addressed to the Virgin Mary, shifts constantly between “thou” and “you” forms, often within the same sentence, depending on the particular degree of intimacy vs. reverence he wants to convey in a particular moment. So they were certainly both available choices when addressing religious figures.

This is the way I learned it in French class in the 1960s. Didn’t know it was changed.

The T-V distinction (that’s the linguistic term for distinguishing between an informal and a formal way of addressing someone) doesn’t exist in Latin; it’s all tu in Latin (at least in its classical form - it might be that postclassical vulgar Latin developed it). I always assumed that it was a general feature of all European languages that have the T-V distinction that in Christian prayers, where God is directly addressed, the informal version is used, to indicate the intimacy that a faithful person has with the creator. FWIW, here’s a Google Books link to a book published in 1800 in francophone Switzerland that has the Lord’s Prayer in the “tu” version in French.

I took French in the mid 1970s, at Catholic school, and the teacher changed it about halfway through. No clue why.