What are the hardest languages to learn? What do think about this?
the most difficult language is the one you never try to learn ;)
Russian & Finnish would be very difficult to learn for me because these languages have a variety of cases in terms of grammar.
In addition, I would like to add German, to quote Oscar Wilde, "Life is too short to learn German."
I think it depends what the learner's native language is. For a native English speaker I agree it would be something like Arabic or Cantonese. Possibly also Native American languages due to difficulty to access learning resources and "native" speakers (no pun intended).
I think Chinese and Arabic are the hardest.
The vocabulary the whales use to communicate is still quite mysterious.
Scientists and daydreamers are scanning through the oceans to
hear a bilingual whale speaking. They are enduring painstaking
efforts for this ambitious goal.