Persian or Farsi
Germans call their language Deutsch. The French call theirs Francais. Spaniards and Latin-Americans refer to theirs as Espagnol.
English-speakers would refer to the above-mentioned languages as German, French, and Spanish respectively.
Similarly, the correct English name for Persian is "Persian"
. In German, Persian is called Persische, in French Persan, and in Spanish Persa.
Native Persian-speakers call their language "Parsi". Due to the lack of the sound 'P' in Arabic, 'F' has substituted 'P'. The Arabic pronunciation "Farsi" has also become mainstream among Persian-speakers.
There is also a cultural, and historical association with Persia, or la Perse. Persia brings to mind Persian Carpets, Persian Poetry, Omar Khayyam, the Silk Road, the Greco-Persian wars, Cyrus, Darius, and Xerxes.
One of most famous works of French literature is the 18th century author Montesquieu's les Lettres Persannes
, or the Persian Letters.
These references and many more, are lost when the term Farsi is used in English or French. The term "farci" in French means "stuffed" as in stuffed tomatoes !
Please refrain from using Farsi when referring to Persian (in English), Persan (in French), or Persische (in German).
Farsi Shekar Ast, Persian is Sugar, is the title of a book written by contemporary Iranian writer Mr. Mohammad-Ali Jamaal-zaadeh (1891-1997).