Mbugu people
The Mbugu people, also known as the Va'maa, Ma'a (Wambugu, in Swahili) are an ethnic Bantu and linguistic group hailing from western Usambara Mountains of Lushoto District in Tanga Region of Tanzania. Tanzania's Mbugu (or Ma'á) language is one of the few true hybrid languages, combining Bantu grammar with Cushitic lexicon. In actuality, the people speak two languages: one mixed and the other Pare, which is closely linked to the Bantu language. They are estimated to be around 60,000 Mbugu people left. Origins
Historically the Mbugu were in the vicinity of Lake Victoria or, less likely, Lake Eyasi. However, his informant used the Swahili phrase bahari ya pili, which means "the other/second sea" and can also refer to a broad plain. As a result, it's possible that the Serengeti was in mind. From there, the Kwavi drove the Mbugu away and followed them to Mugwe in the east. Meinhof speculates that they may have interacted with the Burungi there or nearby. Similar to Mbugu, the Iraqw language spoken by the Burungi as a Southern Cushitic language. The tribe then divided into three sections, traveling once again eastward through Moshi and Same to Lasa in the valley between the western Usambara Mountains and the southern Pare Mountains. Previously, the tribe had been in Ugweno, in the northern Pare Mountains. The tribe was divided into three groups: six clans of Mbugu; six clans each of Nango and Dufu. When the Maasai attacked them at Lasa, they broke off once more: the Dufu moved south into Zigua territory and assimilated into the Zigua; the Nango went to Shume in Usambara and continued to be a Sambaa clan. The remaining group (the six Mbugu clans) reversed into Pare, where they later kept in touch with Vudei for a long time. The Mbugu travelled to Usangi, which is immediately south of Ugweno, but it is unclear at what point they were there. Later, they relocated south once more, this time to Shume in Usambara. Some writers, like Meyer, have used the name Kwambugu to refer to a region in the same general area of Usambara as Shume. They discovered the Nango already established here; later, they expanded into Usambara, reaching Malo, Magamba near Lushoto, and Bumbuli. According to legend, the Mbugu lived in Usambara prior to 1650. The main body of the Mbugu could have followed, possibly not too long after, if the legend that Mbegha, the founder of the Kilindi dynasty in Usambara, had a Nango wife is true. Then Nango must have been established there by the seventeenth century. The following remarks concerning the "Mbugu" give some indications of a perplexed language situation: The "Mbugu" identify as va-ma'a and speak ki-ma'a. The clans that traveled to Usangi solely speak Kipare. Despite having lived in Usambara for more than 200 years, some of the clans there solely speak Kipare. The 'Mbugu' claim that there are no more songs and folktales in their language; all of the proverbs, songs, and tales I gathered were in Chasu. The Wambugu have a distinctive tone when speaking Kipare. There are a few linked families in Magamba' that speak a language that no one can decipher. The Sambaa distinguish between two Wambugu lineages that have entirely different origins. These are from "Umbugwe," also known as Wambugwe, and "Ukwavi-Upare," also known as Wambugu-Makei. Language
The inferences to be made from these sporadic hints would seem to be that while some of the people referred to as Mbugu and identifying as va-ma'a still speak their original language, ki-maa, which is made up of a non-Bantu substratum and a Bantu superstructure, others have completely lost all traces of their native tongue and now speak "Kipare" or "Casu." However, the actual language situation has proven to be a little more complicated. Conclusions that can be drawn from these fragmentary hints indicate that some of the people who go by the names Mbugu and call themselves va-ma'a still speak their original language, ki-maa, which is made up of a non-Bantu substratum and a Bantu superstructure, while others have completely lost all traces of their original language and now speak "Kipare" or "Casu." But it has shown out that the actual linguistic issue is a little more complicated. References

Ethnic groups in Tanzania