Tanzania's population communicates solely through sign language.
Tanzania . Over 100 different languages are spoken in Tanzania , making it the most linguistically diverse country in East Africa . Swahili and English are Tanzania 's official languages . Approximately 10 % of Tanzanians speak Swahili as a first language , and up to 90 % speak it as a second language . Most Tanzanians thus speak both Swahili and a local language ; many educated Tanzanians are trilingual ; also speaking English .