Pronunciation of Vowels in Saterfrisian
Dr. Fort's Spelling

 

Saterfrisian has a four-step system of shorts:
ie           uu     üü
  i       u     ü  
    ä   o     ö    
      a            

 

and of longs:
íe           úu     ü'ü
  ee       oo     öö  
    ää   oa     öä    
      aa            

 

as well as the diphthongs ending in i:
                 
                 
    äi   oi oai   öi  
      ai          

 

and the diphthongs ending in u, uw:
ieuw                  
  eeuw                
    äuw   ou          
      au            

The difference between ie and íe respectively uu and úu as well as üü and ü'ü only applies for e few words.