What language do they speak in Kenya ?
The majority of Kenyans are trilingual, speaking Swahili, English, and at least one of 50+ tribal languages (yes, Americans, feel shame). In Nairobi and on Lamu, it’s not very likely you’ll encounter anyone who doesn’t speak English. Almost all menus, signs, schedules, etc. are printed in English. Of course this isn’t an excuse to not attempt to pick up some Swahili—indeed, that minimal sign of respect for the people in the country we’re visitors in is always appreciated.