The Pashto language (پښتو; alternately, Pashtu, Pukhto, Afghani) is spoken in the southern half of Afghanistan and in western Pakistan. It has approximately 17 million speakers. Like Dari (a close relative of Farsi), it is one of the predominant languages spoken in Afghanistan. It has three major dialects--Eastern, Western Central, and Southern--and is a member of the Indo-Iranian languages family, itself a subgrouping of the Indo-European languages.
The writing system is derived from Arabic via Persian. There are several additional symbols for sounds not found in Persian. Specifically, Pashto has seven vowels rather than five, and it has a series of retroflex consonants.