The languages of Mauritania mainly consist of various Afroasiatic languages, including: Zenaga-Berber, Tamasheq-Berber, Hassaaniya Arabic and Standard written Arabic. French is also used due to colonial influence. Some ethnic minorities speak Niger-Congo languages.

Modern Standard Arabic is the official language of the government of Mauritania. Hassaniyya Arabic is the colloquial spoken variety of Arabic. It is close to the dialect used by the Bedouins. The language serves as a lingua franca. It is also the language of the Imraguen who also use elements of Soninke.

According to Ethnologue, there are 705,500 speakers of French in Mauritania. It serves as a de facto national working language. Mauritania is also a member of the International Organisation of La Francophonie (La Francophonie).

More Info: en.wikipedia.org