English is one of Kenya's official languages (Swahili or KiSwahili is the other one) and is widely spoken throughout Kenya; levels of proficiency are likely to be far lower in remote rural areas or in areas that receive few tourists. Swahili is also very widely spoken, although it is usually a Kenyan's second-language after their tribal tongue. Learning a few words of Swahili or Maa (the language of the Maasai) will be much appreciated by locals.
Taking a Swahili-language course (or any course) entitles you to a ‘Pupil’s Pass’, which is an immigration permit allowing continuous stays of up to 12 months. You may have to battle with bureaucracy and the process may take months, but it can be worth it, especially as you will then have resident status in Kenya during your stay.
ACK Language & Orientation School The Anglican Church runs full-time Swahili courses of varying levels lasting 14 weeks and taking up to five hours a day. Private tuition is available on a flexible part-time schedule.
Language Center Ltd A good Swahili centre offering a variety of study options ranging from private hourly lessons to daily group courses.