Sidaama or Sidaamu Afoo is an Afro-Asiatic language, belonging to the Highland East Cushitic branch of the Cushitic family. It is spoken in parts of southern Ethiopia by the Sidaama people, particularly in the densely populated Sidama Zone. Sidaamu Afoo is the ethnic autonym for the language, while Sidaminya is its name in Amharic. Although it is not known to have any specific dialects, it shares over 64% lexical similarity with Alaba-K'abeena, 62% with Kambaata, and 53% with Hadiyya, all of which are other languages spoken in southwestern Ethiopia. The word order is typically SOV. Sidaama has over 100,000 L2 speakers. The literacy rate for L1 speakers is 1%-5%, while for L2 speakers it is 20%. In terms of its writing, Sidaama used an Ethiopic script up until 1993, from which point forward it has used a Latin script.
The term Sidamo has also been used by some authors to refer to larger groupings of East Cushitic and even Omotic languages. The languages within this Sidamo grouping contain similar, alternating phonological features. The results from a research study conducted in 1968-1969 concerning mutual intelligibility between different Sidamo languages suggests that Sidaama is more closely related to the Gedeo language, which it shares a border with to the south, than other Sidamo languages. According to the Ethnologue, the two languages share a lexical similarity of 60%.
Sidaama vocabulary has been influenced by Ge'ez and Amharic, and has in turn influenced Oromo vocabulary.
In Sidaama, not all noun phrases have nouns. This can occur when it is so obvious what kind of thing the referent of the noun phrase is, that it is unnecessary for the speaker to mention it. Sidaama has two types of noun phrases without nouns. One type is made up only of an adjective or a numeral, where the adjective or the numeral agrees in case, number, and gender with the referent of a noun phrase. This is shown in the examples below:
‘The smart one (masculine) came.’
‘The three (masculine) came.’
The other type of noun phrase without a noun is formed with a noun-phrase clitic, or NPC. This NPC starts with t (FEM) or h (MASC). This is thought to originate from the Afro-Asiatic demonstrative containing t (FEM) or k (MASC). The Sidaama NPC appears in various forms. Which form is used when depends on the gender of the referent of the noun phrase, and the syntactic role or case of the noun phrase. When a noun phrase without a noun is formed with an NPC, both the speaker and the listener know its referent. In this case, the NPC attaches to the end of a genitive noun phrase or relative clause to form a noun phrase without a noun. This is shown in the examples below:
Abebe Gebre-Tsadik. 1985. "An overview of the morphological structure of Sidamo verbs," The verb morphophonemics of five highland east Cushitic languages, including Burji. Afrikanistische Arbeitspapiere 2. Cologne: Institut für Afrikanistik. Pages 64–81.