Central African Republic:
French (official), Sangho (lingua franca
and national language), Arabic, Hunsa, Swahili

Chad:
French (official), Arabic (official), Sara and Sango (in
south), more than 100 different languages and dialects

Chile:
Spanish

China:
Standard Chinese or Mandarin (Putonghua, based on the Beijing
dialect), Yue (Cantonese), Wu (Shanghaiese), Minbei (Fuzhou), Minnan
(Hokkien-Taiwanese), Xiang, Gan, Hakka dialects, minority languages
(see Ethnic groups entry)

Christmas Island:
English, Chinese, Malay

Cocos (Keeling) Islands:
English, Malay

Colombia:
Spanish

Comoros:
Arabic (official), French (official), Comoran (a blend of
Swahili and Arabic)

Congo, Democratic Republic of the:
French (official), Lingala (a
lingua franca trade language), Kingwana (a dialect of Kiswahili or
Swahili), Kikongo, Tshiluba

Congo, Republic of the:
French (official), Lingala and Monokutuba
(lingua franca trade languages), many local languages and dialects
(of which Kikongo has the most users)