The letter is also used in Seneca, Taiwanese Hokkien, Turoyo, and Uyghur when written in Latin script to represent a open mid-front unrounded agomistic vowel.

The words geër ("giver") and geer (a wedge-shaped piece of fabric), for instance, are both pronounced [χiər] in contemporary language.

In some peripheral Emilian dialects, ë is used to represent [ə], e.g. strëtt [strətː] "narrow".

However, a diaeresis above e in German occurs in a few proper names and ethnonyms, such as Ferdinand Piëch, Bernhard Hoëcker, Alëuten, Niuë, Uëa.

Without a diaeresis, ie would be [iː] instead of [iə]; eu would be [ɔʏ] instead of [eu] and ae, oe, ue would be alternative representations of respectively ä, ö, ü. Ë does not belong to the official Hungarian alphabet, but is usually applied in folklore notations and sometimes also in stylistic writing, e.g. is extensively used in the vocal oeuvre of Kodály.

Before or after a double ee, pronounced [eː], to indicate that the ë does not form a digraph with the preceding or following vowel letter but is pronounced separately, for example: gëeegent [ɡəˈʔeːʑənt] ("suitable"), Eeër [ˈeːɐ] ("eggs") or leeën [ˈleːən] ("to lay").

This also applies to French loanwords ending in -ée, e.g. Musée [ˈmyːzeː] ("museum"), n-plural: Muséeën [ˈmyːzeːən], n-less plural: Muséeë [ˈmyːzeːə].

In the corresponding masculine nouns the diaeresis is used in the n-less plural form to distinguish it from the singular of the corresponding feminine noun: Clientë [ˈkliɑ̃ːə] ("customers" [male or gender-neutral], masculine, plural without -n) vs. Cliente [ˈkliɑ̃ːt] ("customer" [female], feminine, singular).

Ë represents the mid central vowel /ə/ in the modern orthography of Piedmontese language.

In some Latin transliterations of Russian such as ISO 9, ë is used for its homoglyph ё, representing a /jo/, as in Potëmkin to render the Cyrillic Потёмкин.

Other translations use yo, jo or (ambiguously) simply e. In the romanization of Syriac, the letter Ë gives a schwa.

Example words that have Ë: knoṭër ("he is waiting"), krëhṭi ("they are running"), krëqdo ("she is dancing"), ŝërla ("she has closed"), gfolëḥ ("he will work"), madënḥo ("east"), mën ("what"), ašër ("believe").

In Seneca, the letter Ë is used to represent /ẽ/, a close-mid front unrounded nasalized vowel.

Ë is the 6th letter of the Uyghur Latin alphabet and represents close-mid front unrounded vowel /e/ (while plain E stands for /ɛ/ or /æ/).