Originally Posted by Aard
I don't know about difficulty, as I know none of the languages you mentioned above. However, Finnish is a member of a completely different language family (Uralic - related, eg, to Hungarian) to those Slavic languages (Indo-European - related to Germanic, Romance, and Celtic languages, Greek, Hindi, and many others). It is generally thought that languages within the same language family are easier to learn. I've studied Japanese, myself, and thought that it was easier than French - it's like learning with a clean slate!
If you're in any way "good" at languages, there is no reason why Finnish should be harder to learn than Russian, Czech, or Polish. Indeed, going by the number of entries in Finnish in Wiktionary, there may well be even more resources online for it.
I agree, Finnish and Russian are completely different. I know people who speak Russian and they say it's pretty easy to learn so I'd say Finnish is harder to learn. But Finnish is just like any other language, it's easy once you get the hang of it.
I think one thing that makes it so difficult and different is that we don't have a lot of prepositions, we use suffixes or whatever they're called.
For example, "to a house, in a house, from a house" would translate as "taloon, talossa, talosta". But still, Finnish is just like any other language, once you learn the basic stuff the rest should be easy. Plus the pronunciation is really easy, there shouldn't be any problems learning to actually speak
Finnish, it's just the grammar part that's a bit tricky.