The Azerbaijani, Azerbaijanian or Azeri language belongs to the western group of the southwestern, or Oghuz, branch of the Turkic language family and is mainly spoken in Azerbaijan and Iran. Azerbaijani is the official language of the Republic of Azerbaijan and over 80% of its population use it as their first language (Johanson 2010). Among non-Persian languages in Iran, Azerbaijani, with approximately 15–20 million native speakers, has the largest number of speakers (Crystal 2010). In total, more than 50 million people speak Azerbaijani (Khalilzadeh 2013).