The vowel inventory varies somewhat between dialects, as the front rounded vowels and are found only in Putèr and Vallader. They have historically been unrounded in the other varieties and are found only in recent loans from German there. They are not found in the pan-regional variety Rumantsch Grischun either. The now nearly extinct Sutsilvan dialects of the Heinzenberg have as in "plànta" 'plant, tree', but this is etymologically unrelated to the found in Putèr and Vallader. The exact realization of the phoneme varies from to depending on the dialect: / 'book'. It is regarded as either a marginal phoneme or not a separate phoneme from by some linguists.