 FACT: There are numerous errors in the use of Latin by priests in  the film. In the scene in St Patricks where Michael Corleone is  honored by the Church, the presiding clergyman pronounces the Latin  word et ("and") as "ay", rhyming with "day", as if it were French.  It is in fact pronounced like its spelled, to rhyme with "wet" and  "pet." Later when Cardinal Lamberto (later Pope John Paul) absolves  Michael Corleone, he ends with the standard "in the name of the  Father," etc., in Latin. But he wraps it up saying "et Spiritus  Sanctus." The correct Latin is "et Spiritus Sancti." But Spiritus is  not a nominative, its the genitive (possessive) singular of a  fourth declension noun, and the correct form of the adjective is  Sancti. Of course these very mistakes wont be noticed by many  viewers, but they will be noticed by anybody who took first year  Latin and/or had any training in the Church.