alt Hacker News> Probably a lot more than just a few months
Maybe, haven't tried so it is hard to say. I do have a background in Greek and Latin as well but I suspect those won't be of much help either nor does the fact that I speak Dutch, German, English, Swedish and French and know some rudimentary Russian get me anywhere.
Spelling and grammar in both Finnish as well as Hungarian seem to be quite regular so it would come down to learning a new dictionary, a bunch of suffixes and the rules when to use which. The dictionary would probably be the hardest since it won't be related to anything I know.
Spelling won't be a problem with either language, pronunciation will (likely) not be an issue with Finnish (depends on how well you handle phonemic vowel length).
Vocabulary will be tough. There are surprisingly many Germanic loanwords in Finnish, both new and very(!) old, but most of them are not obvious until you've studied the language for some time.
Grammar will also be tough. It's not just "a bunch of suffixes".
Some people can communicate really well without being good at the language they are using. I bet you are one of them!