“It is the province of knowledge to speak, and it is the privilege of wisdom to listen.” ~ Oliver Wendell Holmes quotes
You are speaking English, yet I don't understand what you are saying. Does this situation sound familiar?
Each and every language is likely to have multiple dialects. For instance, the English spoken in New York is different than that of the Mid-west US, different than that spoken in Britain, different than that spoken in Kenya. Taking this one step further, the Kiswahili spoken in Nairobi is different from that spoken in Garissa than that spoken in Mombasa (not to mention the slang language sheng which is a combination of English and Kiswahili).
After spending some time in Kenya, you may find yourself adapting your English and your Kiswahili to the local dialect.
To shed light on some of the language differences, let's consider English in Kenya:
Trousers are worn outside, pants are worn inside. [In American English trousers are called pants and pants are called underwear]
A vest is also worn inside. [A vest refers to what I would call an undershirt in the US.]
People don't ask questions, they pose queries.
Instead of walking, I trek or I travel by footing (typically just referred to as footing).
Peanuts cannot be found in Kenya, only 'groundnuts'.
When someone is looking good, they are "smart".
You will fail to find corn, but you will find 'maize'.
Now that you know, you will be better prepared when you come to Kenya.