a Bantu language of the Sabaki branch. In Guthrie's geographic classification, Swahili is in Bantu zone G, whereas the other Sabaki languages are in zone E70, commonly under the name Nyika. Historical linguists consider the Arabic influence on Swahili to be significant, since it takes around 40% of its vocabulary directly from Arabic, and was initially spread by Arab slave traders along East Africa's coast. History Etymology The origin of the word Swahili is its phonetic equivalent in Arabic: Origin The core of the Swahili language originates in Bantu languages of the coast of East Africa. Much of Swahili's Bantu vocabulary has cognates in the Pokomo, Taita, and Mijikenda languages and, to a lesser extent, other East African Bantu languages. While opinions vary on the specifics, it has been historically purported that around 16-20% of the Swahili vocabulary is derived from loan words, the vast majority Arabic, but also other contributing languages, including Persian, Hindustani, Portuguese, and Malay. Omani Arabic is the source of most Arabic loanwords in Swahili. In the text "Early Swahili History Reconsidered", however, Thomas Spear noted that Swahili retains a large amount of grammar, vocabulary, and sounds inherited from the Sabaki language. In fact, while taking account of daily vocabulary, using lists of one hundred words, 72–91% were inherited from the Sabaki language (which is reported as a parent language) whereas 4–17% were loan words from other African languages. Only 2–8% were from non-African languages, and Arabic loan words constituted a fraction of that. According to other sources, around 40% of the Swahili vocabulary comes from Arabic. What also remained unconsidered was that a good number of the borrowed terms had Bantu equivalents. The preferred use of Arabic loan words is prevalent along the coast, where local people, in a cultural show of proximity to, or descent from Arab culture, would rather use loan words, whereas the people in the interior tend to use the Bantu equivalents. It was originally written in Arabic script. The earliest known documents written in Swahili are letters written in Kilwa, Tanzania, in 1711 in the Arabic script that were sent to the Portuguese of Mozambique and their local allies. The original letters are preserved in the Historical Archives of Goa, India. Colonial period Various colonial powers that ruled on the coast of East Africa played a role in the growth and spread of Swahili. With the arrival of the Arabs