Depends on intelligence and language background.

Just begin learning it and then see for yourself, however i have read it is some what in the second category of "hardness", when comparing if italian, french or spanish is in the first category. Suomen kieli ei ole niin vaikea! :)

thank you Mikko so much , that's really was very good answer , and i'm glad to learn Finnish also :) it's very good language and Finnish people are friendly nice to meet you mikko

That is one of the questions I often hear from my foreign friends. But I think that it depends on one's native language. Since Finnish is an extraordinary language and hardly has any "family members" might be the reason for why it's overwhelming for the speakers of other languages to learn it. It'll need a lot of practice to master it, and you need to speak it with a native speaker to become fluent. Practice makes perfect so it is not impossible, though! But what comes to the grammar, we don't usually notice if you make mistakes because it doesn't really matter. As anyone else who speaks Finnish, I'm really happy if you are concidering Finnish as your goal language!