Final answer:
Swahili began as a trade language in East Africa and is now a lingua franca in much of central and east Asia.
Step-by-step explanation:
The language that began as a trade language in East Africa and is now a lingua franca in much of central and east Asia is Swahili.
Swahili originated as a coastal trade language in East Africa, influenced by Arabic and Bantu languages. As trade routes expanded, Swahili spread inland and became a common language of communication between different ethnic groups in central and east Asia.
Swahili is now spoken by millions of people as a first or second language in countries such as Tanzania, Kenya, Uganda, Rwanda, and parts of the Democratic Republic of Congo.
Learn more about Swahili