The official language of Algeria is Arabic. However, if you are an Arabic speaker from the Middle East or you have learnt Modern Standard Arabic (MSA) or another dialect such as Gulf, Iraqi or Levantine then you might struggle to understand the local dialect.
Algerian Arabic mixes elements from French and Berber and is very unique to the region.
Algeria has recently had a resurgence of its Berber identity and along with that has come official recognition of the Berber or Amazigh language similar. Around the country now you will see signs written in the Amazigh script and in certain areas of the country people will speak mainly Amazigh or a mix.
There are many dialects of Amazigh which differ greatly throughout the country. Many people in Algeria do use Amazigh as their main language at home and programs to introduce it to schools and have courses taught in Amazigh are becoming more widespread in both Algeria and neighbouring Morocco.