Pe is the seventeenth letter of the Semitic abjads, including Arabic fāʾ ف‎, Aramaic pē 𐡐, Hebrew pē פ‎, Phoenician pē 𐤐, and Syriac pē ܦ. (in abjadi order). It is related to the Ancient North Arabian 𐪐‎, South Arabian 𐩰, and Ge'ez ፈ.

The original sound value is a voiceless bilabial plosive /p/ and it retains this value in most Semitic languages, except for Arabic, where the sound /p/ changed into the voiceless labiodental fricative /f/, carrying with it the pronunciation of the letter. However, the sound /p/ in Arabic is used in loanwords with the letter pe as an alternative. Under the Persian influence, many Arabic dialects in the Persian Gulf, as well as in Egypt and in some of the Maghreb under the Ottoman influence uses the letter pe to represent the sound /p/ which is missing in Modern Standard Arabic. Not to be confused with the Turned g. The Phoenician letter gave rise to the Greek Pi (Π), Latin P, Glagolitic Ⱂ, and Cyrillic П.

Pe is usually assumed to come from a pictogram of a "mouth" (in Hebrew pe; in Arabic, فا fah).

The letter ف is named فاء fāʾ /faːʔ/. It is written in several ways depending on its position in the word:

In the process of developing from Proto-Semitic, Proto-Semitic /p/ became Arabic /f/, and this is reflected in the use of the letter representing /p/ in other Semitic languages for /f/ in Arabic.

Examples on usage in Modern Standard Arabic:

In Maghrebi scripts, the i'ajami dot in fāʼ has traditionally been written underneath (ڢ). Once the prevalent style, it is now mostly used in countries of the Maghreb in ceremonial situations or for writing Qur'an, with the exception of Libya and Algeria, which adopted the Mashriqi form (dot above). When the letter is isolated or word-final, it may sometimes become unpointed.

The Maghrebi alphabet, to write qāf (ق), a letter that resembles fā’ (ف) in the initial and medial forms is used, but it is really a qāf with a single dot (ڧ‎).