It may surprise some to hear it, but Catholic priests ordained in recent years do not necessarily know a lot of Latin. We all get exposed to a fair amount, and some of us naturally have more aptitude and interest; but it is not taught in the fashion it used to be.
Some may put this down to yet another example of the decadence of the Church, or the horrors of Vatican II, or what-have-you, but it's not that simple.
People don't realize that in the "old days" for which some pine, Latin was taught, not at the graduate-level, but in high school and somewhat in college. (At least so is my understanding.) But high-school are pretty much no more, and college seminaries are rare. Most seminarians enter post-college -- that is, at a point when, in the "old days," they would have already had plenty of Latin.
Having said that, seminaries could do more, I think, to acquaint future priests with the universal language of the Church. So could Catholic high schools, who usually offer Latin, but do not always require it. (Of course, I can imagine the protests of some, and perhaps many, parents to such a requirement.)
Ironically, I was required to take Latin--in a government school! Walnut Hills High School, alma mater mei, still requires Latin--mirabile dictu!
Alas, when I was there, I lacked motivation, so the fruits I have to show for Latin studies are meagre. But my time in the seminary did see me revive my Latin (and learn new pronunciation: VEINy, VEEdee, VEEchee, not WAYnee, WEEdee, WEEkey), and I have continued to work on my Latin since then, currently learning to pray the Office(Liturgia Horarum) in Latin.
One added reason: it keeps my mind agile!