I found out on some sources that the Catholic Church keep using Latin in masses.
Yes the mass continues to be said in Latin, either wholly or in part even today, although the most common practice is to say the entire mass in the vernacular.
Doesn’t that prevent knowing the teachings of Jesus known by Catholics?
Not at all.
First, the teachings of Christ in and through His Church take place in many venues, not just at mass. I attended Catholic grade school for 8 years plus CCD (Sunday school) classes while in high school.
Secondly my family lived the faith - parents, grandparents especially so we were fairly immersed in the teachings.
Third - as someone pointed out above, the mass readings were done both in Latin and then again in the Vernacular and this was followed by a homily in the vernacular and everyone owned a missal containing all the Latin and Vernacular for the mass.
It seemed to persist till the 19th century. Did I get it right? Isn’t it wrong because people wouldn’t understand it?
It did not stop in the 19th century. The official language of the mass is Latin. The Vernacular is used by permission of the Church. The Latin mass (usually in the EF) is still said in many places.
But for the reasons explained above, it is not wrong, and it does not prevent people from knowing the teachings of Christ.
One additional point - during much of the time that the mass was said in Latin as a matter of course, Latin was taught in nearly every school so that most people, if they had much education at all, would have at least a passing knowledge of the language.
Hope this helps.
Peace
James