Stuffs about the difficulties of pronunciations induce more severe stutter are not scientific otherwise there will more PWS in random countries whose native language is more difficult to pronounce, but hitherto, no evidences. Also stutter is not relevant to your lip moving skills or something, cause no evidences manifested PWS's articulations are more retarded than normal people's. I guess you can recollect the most memories of stutter in Swedish and may I ask can you self-analyze what is the root cause of your stutter? Or the firsst time of onset of stutter? I bet you are a psychological PWS.