Everything’s in Latin start to finish. Usually though the priest will reread the Gospel and Epistle in English.
Most people have missals with the Latin and English side by side so they can follow along. So you just start to learn Latin by osmosis. And since most of the Mass stays the same week to week, everybody learns the standard responses and pretty much knows what is going on.
The conservative Lutheran Church Missouri Synod to which I belong has a strong German heritage....stemming from the time of Pastor Martin Luther.
Utilizing a small example, even if we of this generation don't understand German we know the phrase "Stille nacht, heilige nacht" means "Silent night, holy night".
As the poster, Claud, states above, we understand this German phrase and we need no translation because it's understandable to us by the natural "osmosis" he refers to. We know the meaning because we've heard it from baptism through confirmation lessons and beyond. It's just part of our little grey cells.
Many Latin phrases are also ingrained in the Lutheran context....and we understand them completely and treasure them, also.
I fully understand the love Catholics have for the Latin mass. It's their heritage to love it and understand it.....the same as I love and understand my religious heritage.
Gloria in excelsis Deo!
Leni