In which of these countries listed is Swahili NOT the official national language?

Swahili language, also called "kiSwahili", is a Bantu language spoken either as a mother tongue or as a fluent second language on the east coast of Africa in an area extending from Lamu Island, Kenya, in the north to the southern border of Tanzania, in the south. The Bantu languages form a subgroup of the Benue-Congo branch of the Niger-Congo language family.

People who speak Swahili as their sole mother tongue are usually referred to as "Waswahili", but this name refers to their language only and does not denote any particular ethnic or tribal unit. Swahili is widely used as a "lingua franca" in Tanzania, where it is the language of administration and primary education; Kenya, where it is, after English, the main language for these purposes; Congo (Kinshasa), where a form of Swahili is one of the four languages of administration, the main language for this purpose being French; and Uganda, where the main language is English.

There are about 15 main Swahili dialects, as well as several pidgin forms in use. The three most important dialects are "kiUnguja", spoken on Zanzibar and in the mainland areas of Tanzania; "kiMvita", spoken in Mombasa and other areas of Kenya; and "kiAmu", spoken on the island of Lamu and adjoining parts of the coast. Standard Swahili is based on the kiUnguja dialect.