Zjeraar: Frisian is indeed not that hard to understand if you already speak Dutch. Actually, even English shares similarities with the language (which is not all that odd if you know its history). Understanding it is relatively easy. What makes Frisian difficult is when you try to write it. Almost every word involves pairing of consonants you'd never expect to combine and there's constant question which diacritic you have to place on certain vowels. There are certainly rules, but I'm bad at remembering them I guess. In that regard, it's completely different from Dutch.
I agree with Dutch being a much more difficult and irregular language, due to it having lots of rules and exceptions. But although I'm born in Friesland and my parents have always spoken Frisian, I have very few problems with Dutch idiom, grammar and spelling while I have considerably more issues with those of the Frisian language.
By the way, my brother lives in Heerenveen. I live about 12 kilometers away.
It's a small world.
Writing indeed is hard, reading on the other hand is quite easy.
