The official language of Tunisia is Arabic, which is also one of the languages of commerce, the other being French, a heritage of Tunisia as a French protectorate until 1956.The dialect of Arabic spoken in Tunisia, similar to neighbouring Algeria and Morocco, is Maghreb Arabic, which is almost incomprehensible to speakers of the Gulf dialect, so don’t be surprised if you don’t understand the locals even if you know Arabic. However, all Tunisians learn standard Arabic at school, so most locals will be able to communicate in standard Arabic if necessary.
Most of the locals speak Arabic and French. French is the primary language of higher education and is widely used in administration, commerce and the media. English has limited use, but is good for use in tourist areas. Tunisians often use what is called code-switching. This is when two or more languages are used in a conversation or even in a sentence. French and Arabic are used interchangeably.