Which mutually intelligible language groups are spoken by more than 1 million people in Cameroon?

Question

Which mutually intelligible language groups are spoken by more than 1 million people in Cameroon?

Wikipedia is not very helpful. the map below is the most useful thing I found thus far, which teaches me that there are 5 main language families. It doesn't tell me if languages in those families are mutually intelligible and how many people speak those languages.

The reason I want to know is that I'll be in Douala next week and I'd like to spend some time on helping people translate Wikipedia articles about Ebola into African languages. At this point it's not very clear which languages would make sense for that.

Answer 1

This is years late, but offering it anyway:

Ethnologue tends to approach language from what I've heard called a "splitter" perspective, where in effect certain differences are considered sufficient to define separate languages. Where the names (endonyms) used for the languages are also different, that may reinforce the idea of separate languages. In Africa there are many cases of this.

The splitter perspective is not wrong, but it is also possible to work from a more "joiner" perspective, understanding that mutual intelligibility, even if not absolute, is sufficient to identify a larger language. Ethnologue (and the code space SIL manages, ISO 639-3) has a few "macrolanguages" that would be examples, however these were inherited from older coding systems. Ethnologue (nor SIL & ISO 630-3) has not sought to identify macrolanguages beyond that. There are no macrolanguages in Cameroon other than Fula (ff or ful), which of course is only in the north of the country as well as most of West Africa.

The Pan African Localisation project adopted the more joiner approach, informed by that used by some American specialists in African languages and linguistics (notably Prof. David Dwyer, Michigan State U., who compiled a Handbook of African Language Resources, and also the US National African Language Resource Center). One grouping of more or less intelligible languages largely in southern Cameroon goes under the name Beti, and includes among others, Ewondo, Bulu, and Fang.

While Beti is apparently not now a formal language category, and there's some history behind the retired code element for it (btb), it might guide in identifying some important languages that share similarities in structure and vocabulary that could be useful for translation and localization work. The total of all L1 & L2 speakers might be around 2 million. A page on the old PanAfrLoc wiki might be of use, although it needs updating: http://www.bisharat.net/wikidoc/pmwiki.php/PanAfrLoc/Beti

Answer 2

Maybe too late for you, but... The largest language-group of that type is Beti-Fang language (Fang, Bulu, Ewondo, Ntumu, Eton) which is probably large enough; otherwise, there are Douala and Cameroonian Pidgin spoken by a million or more people (and French and English, the official languages), but for the most part, you have to aggregate across languages to get a million speakers and then the languages are not mutually intelligible (such as, the various languages referred to as "Bamileke"). The safest best for Cameroonian languages is that any two languages are not mutually intelligible, and then you can list some exceptions like Ewondo-Bulu etc.