This is a sketch of the phonology of the non-Karo branch of Hamer.
Hamer has six places of articulation for consonants, and eleven manners of articulation, though the system is not entirely orthogonal.
Consonants marked with parentheses are surface forms only, appearing predictably due to phonotactics or morphophonemic processes.
Consonant length is distinctive non-initially. Long /ɾ/ is realized as a trilled /r/.
There are five basic vowels
The vowels are further subdivided into two main categories (with a third being a surface "umlaut" phenomenon (see below)). Category I vowels are shorter, pharyngealized, and have retracted tongue root. Category II vowels are longer, glottalized, and have advanced tongue root.
Vowel Harmony exists in that every root word and every suffix belongs to either category I or II. When the category of a root and its suffix do not agree, a kind of umlauting takes place. An umlauted vowel retains its basic place of articulation, and is pronounced between the corresponding category I and II vowels, i.e. of medium length, and unmarked for pharyngealization, glottalization or tongue root position. Generally, the vowel(s) of the suffix undergo umlauting, but there is a set of "strong" suffixes which retain their category, and cause the vowels of the root to undergo umlauting.
There is a sixth non-phonemic vowel, /ə/, which appears in speech epenthetically to "break up" otherwise invalid consonant clusters. There is no need to consider this a phoneme, and no definitive reason for it to require a grapheme, as it occurs entirely predictably as part of what is essentially an allophonic process.
Syllable structure is simply (C)V(C), though syllable-final consonants are rare. Strings of at least three vowels are documented. Strings of more than two consonants are not documented. There are a large number of (mostly very simple) rules governing metathesis and epenthesis when consonant clusters appear. In summary, there are three sorts of consonant cluster: "valid", "special", and "invalid". Valid clusters undergo no change between their underlying and surface forms. Special clusters undergo some kind of (generally metathetic) transformation in their surface forms. Invalid clusters insert a non-phonemic /ə/ between the two consonants to create their surface forms.
There is no official writing system for Hamer, though several romanization schemes have been proposed, along with a Gə'əz orthography. As yet, there is no movement for official recognition of any of these systems.
This is the romanization used by Jean Lydall. It is perhaps the de facto standard, simply by being the one in which the majority of the existing corpus is presented.
Vowels which have been umlauted are written using the letter for their original sound, combined with an underline.
No marking of stress occurs.
This romanization will be used in this article to present grammar examples. The advantages of this scheme are that it allows capitalization (e.g. of proper nouns), and that it should be more familiar to the general linguist (especially one familiar with African studies).
Within roots, the stressed vowel is marked with an acute (for Category I), a grave (for Category II), a circumflex (for Umlauted Category I) or a caron (for Umlauted Category II). Within "harmonic" suffixes (i.e. where no umlauting takes place), or suffixes which have caused Umlauting, no diacritic is used on the suffix. Within Umlauted suffixes, a circumflex or caron is used as appropriate on the first vowel of the suffix.
Letters are provided below with their traditional Amharic names. Rows marked in dark red have special meanings that cannot fully be explained in the table: the ʾÄlf row is used for Category II vowels without a preceding consonant, while the ʿÄyn row is used for Category I vowels without a preceding consonant.