It is said that Joseph Conrad 1857-1924 considered as the greatest novelists in the English language. He wrote very nice classical novels in English though he spoke with a strong polish accent.It seems to be that any language has a very strong effect on its learners and translators.
But, I see some speakers from Germany like Günther Orth and Sandra Hetzl and others from Russia like Anna koushenco and sobo neina, they speak Arabic nicely just like Arabic native speakers. I really admire their ways and nice accents when they speak. So, some learners and translators from specific countries have a great accent when they speak specific languages whereas some cannot be good though they are great when they write something.
My question is, do you think some tongues of some languages are more flexible than others or it is just a talent or skill of a learner?