The Bering strait dialect has a fourth vowel /e/, which preserves the fourth proto-Eskimo vowel reconstructed as */ə/. In the other dialects, proto-Eskimo */e/ has merged with the closed front vowel /i/. The merged /i/ is referred to as the “strong /i/”, which causes palatalization when preceding consonant clusters in the North Slope dialect (see section on palatalization below). The other /i/ is referred to as “the weak /i/”. Weak and strong /i/s are not differentiated in orthography, making it impossible to tell which ⟨i⟩ represents palatalization “short of looking at other processes which depend on the distinction between two i's or else examining data from other Eskimo languages”. However, it can be assumed that, within a word, if a palatal consonant is preceded by an ⟨i⟩, it is strong. If an alveolar consonant is preceded by an ⟨i⟩, it is weak.