How did Arabic influence the vocabulary of Swahili?

Swahili, a member of the Bantu branch of the Niger-Congo language family, has been significantly influenced by Arabic through centuries of contact between Arabian traders and the inhabitants of the East African coast.1

This interaction resulted in the incorporation of an enormous number of Arabic loanwords into the Swahili vocabulary. The name of the language itself is derived from the Arabic word sawāḥilī, which is the plural adjectival form of a term meaning "of the coast".12

While Swahili maintains a characteristically Bantu grammatical structure and a large base of vocabulary roots from its Bantu origins, the influence of Arabic expanded as the language served as a lingua franca for Arab ivory and slave caravans, which helped spread the language inland during the 19th century. Additionally, the earliest preserved Swahili literature, dating to the 18th century, was recorded using the Arabic script, although the language is now written using the Roman alphabet.1