I second this. I tried it in Italian (my native language), it doesn't really make obvious mistakes but the phrasing is often awkward and robotic, and it tends to "overcorrect" sentences when in fact they are correct and idiomatic Italian.
It also somehow tried to convince me to visit Galleria Borghese in Rome to see Michelangelo's David and The Birth of Venus (they are in fact at the Galleria dell'Accademia and at the Uffizi respectively, in Florence). But I guess that's par for the course for LLMs.
Don't get me wrong, I like math and had fun skimming through the book. But 4 pure math chapters to get to "growing circles"? Really?
It feels like these algorithms can be explained using much simpler terms.
Portuguese and Russian natives don't speak like that. The phrasing is incorrect.