Latin Small Letter W
The only letter in the English alphabet whose name has three syllables — "double-u" — lowercase 'w' carries its own origin story in its very name, descending from a medieval ligature of two 'v' or 'u' characters written side by side. It is the twenty-third letter of the Latin alphabet and accounts for roughly 2.4 % of characters in typical English corpora. In ASCII it sits at code point 119 (0x77), positioned 32 above its uppercase counterpart 'W' at 87 (0x57), maintaining the single-bit case offset (bit 5) shared by all ASCII A–Z / a–z pairs.
Technical Details
Code Example
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// Write mode for filesFILE *f = fopen("output.txt", "w"); // Write modefprintf(f, "Hello, World!\n");fclose(f);
Common Usage
Regex word-character shorthand: In most regex engines, \w is the shorthand class for 'word characters' — typically matching letters, digits, and the underscore. In ASCII mode this usually expands to [a-zA-Z0-9_], while Unicode-aware modes (the default in Python 3 and several other implementations) extend it to accented letters and non-Latin scripts. Its counterpart \W matches any character that is not a word character.
Historical letterform: The glyph originated as a ligature of two 'u' or 'v' characters (VV or UU) in early medieval writing, gradually fusing into a single letter. English preserves the 'u' origin in the name 'double-u', while French 'double-v' and the German informal 'Doppel-v' reflect the pointed form instead. It emerged as a fully distinct letter during the late medieval period, making it among the last additions to the standard Latin alphabet.
Peripheral status in Romance languages: Unlike most Latin-alphabet consonants, 'w' is not considered a native letter in several major Romance languages — French, Spanish, Italian, and Portuguese use it almost exclusively in loanwords and foreign proper nouns (e.g., French 'wagon', Spanish 'whisky'). This peripheral status has led some dictionaries and spelling authorities to treat it historically as a foreign import rather than a full member of the alphabet.
Diacritical variants: Welsh treats 'w' as a vowel (representing /uː/ or /ʊ/) and applies the full set of Welsh vowel diacritics to it — ŵ (circumflex), ẁ (grave), ẃ (acute), and ẅ (diaeresis) — making it the language with the richest diacritical use of 'w'. Outside Welsh, ẇ (dot above) appears in some transliteration and scholarly contexts, but the letter's diacritical family remains small compared to vowels like 'a' or 'e'.
Regex word-character shorthand: In most regex engines, \w is the shorthand class for 'word characters' — typically matching letters, digits, and the underscore. In ASCII mode this usually expands to [a-zA-Z0-9_], while Unicode-aware modes (the default in Python 3 and several other implementations) extend it to accented letters and non-Latin scripts. Its counterpart \W matches any character that is not a word character.
Historical letterform: The glyph originated as a ligature of two 'u' or 'v' characters (VV or UU) in early medieval writing, gradually fusing into a single letter. English preserves the 'u' origin in the name 'double-u', while French 'double-v' and the German informal 'Doppel-v' reflect the pointed form instead. It emerged as a fully distinct letter during the late medieval period, making it among the last additions to the standard Latin alphabet.
Peripheral status in Romance languages: Unlike most Latin-alphabet consonants, 'w' is not considered a native letter in several major Romance languages — French, Spanish, Italian, and Portuguese use it almost exclusively in loanwords and foreign proper nouns (e.g., French 'wagon', Spanish 'whisky'). This peripheral status has led some dictionaries and spelling authorities to treat it historically as a foreign import rather than a full member of the alphabet.
Diacritical variants: Welsh treats 'w' as a vowel (representing /uː/ or /ʊ/) and applies the full set of Welsh vowel diacritics to it — ŵ (circumflex), ẁ (grave), ẃ (acute), and ẅ (diaeresis) — making it the language with the richest diacritical use of 'w'. Outside Welsh, ẇ (dot above) appears in some transliteration and scholarly contexts, but the letter's diacritical family remains small compared to vowels like 'a' or 'e'.