That depends as much as anything on the writing system employed. I have no
hope of understanding anything in Russian or Eastern European languages
where the conventional writing system is Cyrillic, because similar though
Cyrillic is to the Latin alphabet it's not similar enough to be readable.
(Not to me, at least.)
(Of course, if I actually cared about this I suppose I could always learn
Cyrillic, but I'm English so it's traditional that I be monoglottal