P — Sixteenth letter of the Latin alphabet

Form and pronunciation

The capital form P consists of a vertical stem with a bowl attached at the top right; the lowercase p extends below the baseline in many typefaces. In phonetic terms, P commonly represents /p/. In English, initial /p/ is typically aspirated (a burst of breath) while it can be unaspirated or unreleased in clusters or final position. Different languages may assign slightly different phonetic values.

History and origin

The letter traces its ancestry to the Semitic letter "pe," often signifying "mouth," which passed into the Greek alphabet as pi and then into Etruscan and Latin forms. Over centuries type designers and scribes established the familiar shapes used today.

Uses and symbols

• In writing: a basic alphabetic letter (letter) for many languages.
• Science and math: uppercase P denotes sets or probability classes (for example, the complexity class P), lowercase p often denotes pressure or probability or momentum.
• Chemistry: P is the chemical symbol for phosphorus.
• Music and notation: the dynamic marking p means "soft" (piano).
• Informal writing: the emoticon ":P" (see emoticons) is used to indicate a playful or joking expression.

Beyond these functions, P appears as an initialism and symbol in signage, grades ("P" for pass), and abbreviations. Typographic variants, ligatures, and script forms exist in specific contexts, and the letter is closely related historically to Greek Π and other alphabetic relatives.

For concise reference, P occupies a stable place in the Latin-derived scripts and continues to serve diverse roles in language, science, and everyday symbolism.

See also: general discussion of the alphabet and alphabetical ordering, and further entries on letters and symbols (letter).