Generally speaking, Japanese is one of the hardest languages for native English speakers to learn. At the same time speaking English is so difficult for most Japanese people. I have heard some native English speakers told me they couldn't read Japanese articles despite they have good conversational skills in Japanese. However, I don't think it is too hard for you guys to speak Japanese even if your mother tongue is English. In fact a lot of native English speakers do communicate with us in Japanese.
I don't think you can simply go by a number, Nico.
Comparing Korean and Japanese, I'd definitely say Japanese is the harder one.
English is probably the simpliest language on earth though.
Since both German and Turkish are my mother tongues, I can compare both and would say that Turkish aggulitations might be extremely challenging for foreigners to learn.
I wouldn't say German is that hard though, despite all the "fear" of German. It's just very specific - unlike English.
For an English speaker, I really don't think Russian is the hardest language. The writing system isn't that difficult because many letters are still the same as in English. It didn't take me very long to learn Cyrillic at all.
My friend (who speakers Arabic) taught me the Arabic alphabet and pronunciation once. I think that was much harder than Russian.
i think there is no difficult langauge to learn it's just depending on if u are really wanna learn this langauge
I know a few British people who speak Japanese. :) I don't know how well they speak the language though. If it is as difficult as Russian then I may never speak it!
Russian is category 3 like Japanese. Korean and Arabic are category 4.