Persian alphabet

The Persian alphabet () or Perso-Arabic script, is a writing system used for the Persian language spoken in Iran (Western Persian) and Afghanistan (Dari Persian). The Persian language spoken in Tajikistan (Tajiki Persian) is written in the Tajik alphabet, a modified version of Cyrillic alphabet since the Soviet era.
The Modern Persian script is directly derived and developed from Arabic script. After the Muslim conquest of Persia and the fall of Sasanian Empire in the 7th century, Arabic became the language of government and especially religion in Persia for two centuries.
The replacement of the Pahlavi scripts with the Persian alphabet to write the Persian language was done by the Saffarid dynasty and Samanid dynasty in 9th-century Greater Khorasan. It is mostly but not exclusively right-to-left; mathematical expressions, numeric dates and numbers bearing units are embedded from left to right. The script is cursive, meaning most letters in a word connect to each other; when they are typed, contemporary word processors automatically join adjacent letter forms.
Letters.
Below are the 32 letters of the modern Persian alphabet. Since the script is cursive, the appearance of a letter changes depending on its position: isolated, initial (joined on the left), medial (joined on both sides) and final (joined on the right) of a word.
The names of the letter are mostly the ones used in Arabic except for the Persian pronunciation. The only ambiguous name is , which is used for both and . For clarification, they are often called (literally "-like " after , the name for the letter that uses the same base form) and (literally "two-eyed ", after the contextual middle letterform ), respectively.
Overview table.
Historically, there was also a special letter for the sound . This letter is no longer used, as the /β/-sound changed to /b/, e.g. archaic /zaβān/ > /zæbɒn/ 'language'
Letter construction.
 The i'jam diacritic characters are illustrative only, in most typesetting the combined characters in the middle of the table are used.
 Persian Yē has 2 dots below in the initial and middle positions only. The standard Arabic version always has 2 dots below.
Letters that do not link to a following letter.
Seven letters (, , , , , , ) do not connect to the following letter, unlike the rest of the letters of the alphabet. The seven letters have the same form in isolated and initial position and a second form in medial and final position. For example, when the letter is at the beginning of a word such as ("here"), the same form is used as in an isolated . In the case of ("today"), the letter takes the final form and the letter takes the isolated form, but they are in the middle of the word, and also has its isolated form, but it occurs at the end of the word.
Diacritics.
Persian script has adopted a subset of Arabic diacritics: zebar ( in Arabic), zir ( in Arabic), and piš "or" ( in Arabic, pronounced "zamme" in Western Persian), tanwīne nasb and šaddah (gemination). Other Arabic diacritics may be seen in Arabic loanwords in Persian.
Short vowels.
Of the four Arabic short vowels, the Persian language has adopted the following three. The last one, sukūn, has not been adopted. 
In Iranian Persian, none of these short vowels may be the initial or final grapheme in an isolated word, although they may appear in the final position as an inflection, when the word is part of a noun group. In a word that starts with a vowel, the first grapheme is a silent "alef" which carries the short vowel, e.g. ("omid", meaning "hope"). In a word that ends with a vowel, letters , and respectively become the proxy letters for "zebar", "zir" and "piš", e.g. نو ("now", meaning "new") or بسته ("bast-e", meaning "package").
Tanvin (nunation).
Nunation (, ) is the addition of one of three vowel diacritics to a noun or adjective to indicate that the word ends in an alveolar nasal sound without the addition of the letter nun.
Other characters.
The following are not actual letters but different orthographical shapes for letters, a ligature in the case of the . As to ("hamza"), it has only one graphic since it is never tied to a preceding or following letter. However, it is sometimes 'seated' on a vâv, ye or alef, and in that case, the seat behaves like an ordinary vâv, ye or alef respectively. Technically, "hamza" is not a letter but a diacritic.
Although at first glance, they may seem similar, there are many differences in the way the different languages use the alphabets. For example, similar words are written differently in Persian and Arabic, as they are used differently.
Novel letters.
The Persian alphabet has four extra letters that are not in the Arabic alphabet: , ("ch" in "chair"), ("s" in "measure"), .
Deviations from the Arabic script.
Persian uses the Eastern Arabic numerals, but the shapes of the digits 'four' (), 'five' (), and 'six' () are different from the shapes used in Arabic. All the digits also have different codepoints in Unicode:
Word boundaries.
Typically, words are separated from each other by a space. Certain morphemes (such as the plural ending '-hâ'), however, are written without a space. On a computer, they are separated from the word using the zero-width non-joiner.
Cyrillic Persian alphabet in Tajikistan.
As part of the "russification" of Central Asia, the Cyrillic script was introduced in the late 1930s. The alphabet remained Cyrillic until the end of the 1980s with the disintegration of the Soviet Union. In 1989, with the growth in Tajik nationalism, a law was enacted declaring Tajik the state language. In addition, the law officially equated Tajik with Persian, placing the word "Farsi" (the endonym for the Persian language) after Tajik. The law also called for a gradual reintroduction of the Perso-Arabic alphabet.
The Persian alphabet was introduced into education and public life, although the banning of the Islamic Renaissance Party in 1993 slowed adoption. In 1999, the word "Farsi" was removed from the state-language law, reverting the name to simply "Tajik". the "de facto" standard in use is the Tajik Cyrillic alphabet, and only a very small part of the population can read the Persian alphabet.
Proposed Latin alphabet.
Anwar Wafi Hayat, Afghan writer and researcher, proposed new Latin alphabet in 2019, called Rumi script for Dari Persian spoken in Afghanistan. His research revealed the various reading and writing problems with the current Perso-Arabic script adding that the script has slowed down literacy acquisition and hiked the poverty rate. Based on his study, the new Rumi Persian alphabet will improve literacy acquisition and help in digitizing the Persian language and will also help the foreigner learners of Persian to learn this language easily and quickly.  The Rumi Persian alphabet contains 32 letters.
Example of Persian text in Rumi Persian script.