Translation:My grandfather was a teacher in a junior high school.
The first does not exclude the second.
That means that he worked as a teacher OF the junior high school.
So, he could teach IN that school.
"My grandpa was a teacher of the junior high school" doesn't sound like natural English..."at the junior high school" is much better.
Well it shows that he was a teacher at this level of education and not a specific school - and this of course makes sense, so added.
In Britain , despite May's efforts grammar schools are pretty well obsolete. The acceptable answers for gymnasium and and lyceum in England and Wales are Comprehensive school and for gymnasium sixth form college. Although High school and academy and simplycollege are replacing these words. It' abit of a minefield trying to express titles for levels of schools in foreign languages
Myślałem, że gymnazjum jest za nowy koncept w polskim systemie edukacijnym i dlatego tam dziadek nie mogł być nauczycielem. Albo pred tym było gymnazjum coś innego?
this is complicated. your grandfather could have been a teacher in "gimnazjum" It used to be a junor high school and high school combined ( age 10-18) in years 1918-1932 and junior high schools after 1932 (class III-VI of the former one) . they stopped functioning during the II World War, and then were closed down. in 1948.
also before I World War the equivalents of high school in partitions countries were also called "gimnazjum" in Polish.
also gimnazjum in its current form has been around for 16 years, so if your grandpa is young enough it is possible too.
no worries, our government started to "remove" (sorry for my english) gimnazjum. in next years they will change our education system, and we will have 8 years of elementary school and 4/5 years of high school
Could "My grandpa was a gym teacher" also work as an answer here? I find that that people very rarely use the long form of "gymnasium" in conversation.
No no no no. That's a false friend. "Gimnazjum" doesn't have anything to do with gym. Well, almost nothing - it should have a gym. It's a middle school, years 7, 8 and 9 of our education. It's about to vanish soon, most probably.
"gymnasium" = "gym" in school, as the room where you have physical education, is either "sala gimnastyczna" (especially if you do basketball, volleyball and similar there), or "siłownia" (the one with weight-lifting and other devices).
When you're "going to the gym" after work, that's definitely "siłownia".
So, why doesn't high school work? Or am I confusing things with the german gymnasium?
ah, so gimnazjum (pl) = grammar school + first part of secondary school (uk) = junior highschool (usa) = collège (fr) = first part of gymnasium (de) and liceum (pl) = high school (usa) = lycée (fr) = second part of secondary school (uk) = second part of gymnasium (de). Is this right?
Frankly, I have no idea, your list just made my head dizzy :D I can only precise it the way I did already.
Anyway, most probably "gimnazjum" will not be a thing anymore in a few years, we're supposed to go back to the old system of 8 years of szkoła podstawowa and 4 years of liceum.