Kenya reads it in English
Papers filed in Kenya have to be in English, so anything issued in another language needs rendering before it can be read there. That much is simple. The confusion starts one step earlier, with the word certified, which is doing two quite different jobs on most checklists and sends people to the wrong counter for the wrong piece of paper.
Two certifications, two questions
A certified copy answers a question about the paper: is this a true reproduction of a record that exists? A signed translation answers a question about the words: does this English say what the source said? Neither stands in for the other, and a stamp on a photocopy has never once told a reader in Kenya what the text underneath it actually means.
What the certificate of accuracy says
The signed page attached to the work gives the translator's name, the date, the language pair and the sheet it was taken from. It claims a match between two texts and claims nothing beyond that. It does not say your record is genuine, it does not rank the body that issued it, and it makes no promise about how anyone will treat what the record contains.
Getting the copy before the English
Because the English is written from whatever sheet you supply, the copy has to come first. Where the record is a birth, marriage or death entry, Bristol Register Office at The Old Council House, Corn Street, Bristol BS1 1JG issues fresh certified copies, so your own paper stays exactly where it is. The rate is £25 a side, with 2–3 business days standard and 24 hours express.