English is Sierra Leone's official language, and is commonly used in the business world. Arabic and French are other languages from abroad that may be useful.
It is beneficial to have familiarity with Krio, which is most widely spoken throughout the country. Foreigners' attempts to speak it are often appreciated. Krio is an amalgamation of English, French, and local west African languages. Unlike pidgin languages, however, Krio is fully formed in scope of use, and in grammatical structure. While it is possible to learn basic Krio through book, CD, and online study, Krio is best learned from native speakers.