The letter F (uppercase F, lowercase f), pronounced "ef," is the sixth letter of the classical Latin alphabet and one of its consonants. In most modern languages that use the Latin script the letter denotes the voiceless labiodental fricative sound, represented in the International Phonetic Alphabet as [f]. Its voiced counterpart is /v/, written with the letter V in many languages. The name "ef" is used in English and several other languages; in sign languages the manual alphabet sign for F is commonly made by touching the thumb and index finger to form a circle while the other three fingers remain extended.

Characteristics and orthography

Visually, the uppercase F consists of a vertical stroke with two shorter horizontal bars; the lowercase f has a more complex form and often descends below the baseline in serif types. Historically, the lowercase f has been confused with the long s (ſ) in older typefaces, but they are distinct letters. In handwriting and modern digital fonts the shapes of F and f vary widely, including italic and cursive forms. Several digraphs and letter combinations in different languages involve f: for example, English uses the digraph "ph" to represent the /f/ sound in many Greek-derived words, while Welsh distinguishes between f (/v/) and ff (/f/).

Historical development

The ancestry of F can be traced back to early Semitic scripts. A pictographic sign that likely represented a hook or club evolved into the Phoenician letter Waw, which originally denoted a consonant like /w/. The Phoenician sign then influenced the early Greek alphabet. In Greece the symbol was adapted in two different ways: one descendant became the digamma (used for the sound [w] in early dialects and later preserved as a numeral for 6), and another evolved into upsilon to represent vowel values.

The Etruscans, borrowing from early Greek letterforms, adopted characters to suit the phonemes of their language. Because Etruscan had a native /f/ sound not present in Classical Greek, they used combinations of existing signs and eventually introduced a distinct grapheme for /f/ in their script. When the Romans derived their alphabet from Etruscan models, they simplified and standardized forms to produce the F glyph used in Latin inscriptions and manuscripts. Elements of these intermediate Etruscan and early Roman signs are represented here for reference:

Phonetics and frequency

Across languages the primary value associated with F is the voiceless labiodental fricative [f], produced by directing air through a narrow gap between the lower lip and upper teeth. In languages where both /f/ and /v/ occur, they form a voiceless–voiced pair (e.g., English, German). The relative frequency of the letter F varies by language: it is moderately uncommon in many European languages, tending to rank in the lower half of letter-frequency lists (for example, in German texts it appears at roughly one to two percent of letters). Orthographic conventions, loanwords and historical sound changes influence how often F appears in any given language.

Uses, symbols and notable facts

  • As a symbol, F is widely used outside alphabetic contexts: in physics it commonly denotes force, in mathematics it often names functions, and in music it denotes the pitch and key of F.
  • In computer encodings the Latin letter F occupies fixed positions in ASCII and Unicode, with distinct code points for uppercase and lowercase forms; it is also one of the characters used in hexadecimal notation to represent the value fifteen (15).
  • Typographic and editorial conventions include the abbreviation "f." and "ff." in citations; in bibliographic usage "f." means "and the following page," while "ff." means "and the following pages."
  • Several proper nouns, technical terms and names use the letter F alone as an identifier (grades, labels, model names), and it appears as a letter-name entry in spelling alphabets such as the NATO phonetic alphabet, where it is represented by the word "Foxtrot."

F should be distinguished from similar letters and historical forms: the modern F is separate from the early Greek phi (which originally represented an aspirated p and later shifted to an /f/ sound), and different from digamma, upsilon and other archaic signs that share a common ancestry. In many alphabets derived from Latin the sound and usage of F have been preserved, while in some languages historical developments have reassigned values or produced alternate spellings for the same sound.