Yea but they sound exactly like ours, but with the opposite meaning. :)

Languages that aren't Indo-European are generally pretty difficult for those of us who grew up speaking an Indo-European language. The problem is that many are deceptively simple but maddeningly subtle. Japanese and Korean certainly fit that description; Mandarin probably does too.

Arabic is another seemingly simple language, but it has many dialects, and speaking the wrong dialect (or worse, speaking academic Arabic) immediately pins on you the badge of "outlander".

And, curious as I always am, what's the reason for everyone learning "difficult" languages? Professional reasons (are you linguists f.e.)? Business reasons? Do you travel a lot and need to communicate in different languages?

I am asking because, English being the common universal language nowadays, I really don't know if it's really worth it to learn one or two more languages, that I may eventually forget if I don't practice them frequently.

2-croatian,english
not sure if it counts,because they are basicly the same,then bosnian,serbian,a little bit slovenian

Sadly, I haven't gone very far with any attempts to learn difficult languages (I'm already busy enough trying to improve the 'easier' ones I know) but I have been tempted a few times.

You already named a few reasons, personal relations could be another one, and some people also just enjoy learning languages for the fun of it.

Besides, by learning a new language you can get to know the people who speak it and the culture that's based on it better, so it widens your horizon. You can try to translate everything into English or your native language but it's not the same. You won't quite get the way of thinking, the humor, the nuances etc. And not everything is translated into other languages either, so if for example you're very interested in Japanese culture, movies, mangas whatever, it can be beneficial to know Japanese even if it's got nothing to do with your job.

Hebrew, English, Yiddish

I´ve studied hebrew in the past, but I´ve forgot most of it.

אני צריך לתרגל את העברית שלי
:-)
Greetings

sounds great from here! :) if you are interested in exercising it, I'd be more than happy to help.

and this
http://wiki.answers.com/Q/What_is_the_sapir-whorf_hypothesis (or the long version http://en.wikipedia.org/wiki/Linguistic_relativity)
Don't take the strong form seriously, the weak form has some truth to it.

Anyway, learning any additional language expands your mind. Especially those that belong to a different family, they can force you to construct your thoughts in a radically different manner. Personally i find it immensely fun. I love the grammatical parts the most - it's all about rules, patterns, combinations, logic. The more rule-based, complex and "exotic" the language the more fun it is, and the more the sense of accomplishment you get once you get the hang of it. Same goes for the pronunciation. But I guess I'm some sort of a language geek. As far as practicality goes, it's awesome if you like reading (or watching movies). I don't want to repeat what has been said, but a lot tends to be lost in the process of translation. Especially with some books. Imagine reading translations of Terry Pratchett's books x_x

Heh, actually that's the exact reason I started teaching myself to read books in English when I was a kid, to experience the original humour of Terry Pratchett. :D

finnish, english, some swedish and a bit of german :)

Russian (it's my native), English, German and a (very) little bit Breton.
There're also two more languages, but as long as they're dead ones (Ancient Greek and Latin), I can't actually tell that I speak them :)

Japanese and Chinese are actually not related languages at all (not in the same "language group".) Though Japanese and Korean are very distantly related (very distantly. Not even as close as the Romance languages.) But they may seem similar in writing as Japanese took Chinese characters and tried to adapt it to their own language (badly.)

As to your question... I guess you'd just have to study the language to see the differences? I don't know, I've been studying since I was 14 (27 now) so I have a hard time imagining the language from an outsider's point of view. Though there are some characters that are very close, and particularly if the text is small it can be hard to distinguish between one and the other. But normally they aren't so similar as to not be able to tell the difference, and even if they are, you can usually tell from context.

I wouldn't give too much thought to the Whorfian hypothesis, as revolutionary as it was at the time, it doesn't bear out in real life. It fails to handle the other situations gracefully. As in it's more likely that culture and language both affect each other, but the hypothesis really only handles it going in one direction.

English and a small bit of french.