I guess that you can create a redirection rule in your .htaccess file to do that, although this is not how it is supposed to work, in the case you just described the proper way is to write the blog in French, and translating it to English, problem solved…
Mimi nadhani kwamba unaweza kujenga utawala redirection katika faili yako htaccess. Kufanya hivyo, ingawa hii si jinsi zinatakiwa kufanya kazi, katika kesi tu ilivyoelezwa njia sahihi ni kuandika blog kwa Kifaransa, na kutafsiri kwa Kiingereza, tatizo kutatuliwa…