Swahilization or Swahilisation refers to one of two practices: Swahili was the language spoken throughout the coastal tribes of Eastern Tanzania before the arrival of the European settlers.
[1] By the 1990s, the Swahilization of the Tanzanian education system did not really happen, English remaining a dominant academic language, and many reforms were abandoned.
In the country's justice courts, trials were led in Swahili but the archives were maintained in English.
The mix of Swahili and English in the country's spoken languages was called Kiswengli (Kiswahili-English).
[2] 2010 studies have shown that, in Tanzania, Swahili became predominant in the regions that traditionally spoke Matengo.