The present system of writing Navaho employs only one diacritical to
express four tonal variations. This is the acute accent mark (´). If a
short vowel or n, both elements of a long vowel or a diphthong are
marked thus the tone indicated is high. If only the first element of a
long vowel or diphthong is marked the tone is falling from high, and if
only the last element is marked the tone is rising from low. When a
vowel, diphthong or n is unmarked the tone is low. The difference
between low and high tone in Navaho is similar to the difference in tone
of "are you" and "going" in the English question "are you going?"
'azee' (medicine) low tone
'azéé' (mouth) high tone
háadish? (where?) falling tone
shínaaí (my elder brother) rising tone