Perhaps but there are other Catholic countries that have nowhere near the amount of anti-Semitism Poland has.
No Catholic country had 3 million Jews and definitely no Catholic country was forced by an occupier to accommodate the Jews thrown out from the occupier's country (tsarist Russia):
Such unnatural concentration of people from one ethnicity, religion, culture, probably quite often even not knowing Polish language created tensions in overpopulated towns (Jews for some time weren't allowed to settle in the countryside) and brought poverty and antagonisms in already poor and undeveloped Russian partition (this part of Poland is still called "Poland B" nowadays, since it's still poorer and more undeveloped than "Poland A").
The Jews assimilated very well.
Some did, some didn't.
They learned the language better than the average Pole.
All of them?
I remember reading an article in a Polish newspaper "Gazeta Wyborcza" - I think it was an interview with Simcha Rathajzer-Rotem aka "Kazik", who came to Poland from Israel to take part in the commemoration of the 70th anniversary of the Warsaw Ghetto Uprising (he's one of the three still alive participants of the uprising). He (if I remember right) was saying that the greatest chances of surviving usually had those Jews who not only knew Polish language, but also spoke it without accent and who had Polish friends - in other words, as we would call it nowadays, those who integrated. If you watched an interview with Władysław Szpilman (the protagonist of Roman Polański film "The Pianist") you would know he was one of such Jews.
It would clearly mean that there were those who didn't speak Polish. Not really surprising considering how big Jewish communities were in some places.
I also vaguely remember a young Jewish character from one of the Polish novels that are (or were when I was going to highschool) part of compulsory reading for Polish classes (the author was probably Żeromski or Prus perhaps, I don't remember) - through this character, if I remember correctly, apparently the dilemma of young Jewish people was presented - to assimilate or not to assimilate into the Polish society.
The reason for this dilemma is pretty clear for most Polish people, I imagine.
Patrycja, I think you're either rather ignorant or you aren't Polish... o_O
Many of my family members and friends back home say disgusting anti-Semitic things.
Where are you from?
the greatest chances of surviving
surviving the Holocaust, of course