KISWAHILI DURING 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 in East Africa, they used Swahili as a language of trade as well as for teaching Islam to the local Bantu peoples. This resulted in Swahili first being written in the Arabic alphabet.
The later contact with the Portuguese resulted in the increase of vocabulary of the Swahili language. The language was formalised in an institutional level when the Germans took over after the Berlin conference. After seeing there was already a widespread language, the Germans formalised it as the official language to be used in schools. Thus schools in Swahili are called Shule (from German Schule) in government, trade and the court system. With the Germans controlling the major Swahili-speaking region in East Africa, they changed the alphabet system from Arabic to Latin.
After the first World war, Britain took over German East Africa, where they found Swahili rooted in most areas, not just the coastal regions. The British decided to formalise it as the language to be used across the East African region (although in British East Africa [Kenya and Uganda] most areas used English and various Nilotic and other Bantu languages while Swahili was mostly restricted to the coast). In June 1928, an inter-territorial conference attended by representatives of Kenya, Tanganyika, Uganda, and Zanzibar took place in Mombasa. The Zanzibar dialect was chosen as standard Swahili for those areas, and the standard orthography for Swahili was adopted.