The pronunciation of R varies considerably from dialect to dialect and even between speakers in the same dialect area:
- An alveolar trill [r], with the alveolar tap [ɾ] as a common allophone. (aka Spanish R)
- The uvular trill [ʀ], found particularly in the central and southern dialect areas. Syllable-finally, it may be debuccalized to [ɐ], much as in German. This is more common in the (south)eastern areas (Limburg, southeast Brabantian, Overijssel). (aka German R)
- The coastal dialects of South Holland produce a voiced uvular fricative [ʁ] (aka French R), which causes it to merge with a uvular /ɣ/ and (if devoicing occurs) with /x/. In these dialects, schijven ('discs') and schrijven ('to write') are homophones.
- The retroflex approximant [ɻ] or "bunched approximant" is found at the end of a syllable by some speakers in the Netherlands, especially those from the Randstad, but not in Belgium. Its use has been increasing in recent years. In the Leiden dialect it is used everywhere in a word. (+- English R)
Conclusion: Don't worry if you can't roll your r's. Try the German or French one instead, if that's easier for you. :)