Look up O, o in Wiktionary, the free dictionary.

Basic Latin alphabet
Aa Bb Cc Dd   Ee Ff Gg Hh Ii Jj Kk Ll Mm Nn Oo Pp Qq Rr Ss Tt Uu Vv   Ww Xx Yy Zz

O is the fifteenth letter of the modern Latin alphabet. Its name in English is spelled o (pronounced /oʊ/), plural oes.^[1]

History

Egyptian hieroglyph `ir	Proto-Semitic O	Phoenician O	Etruscan O	Greek Omicron

The letter was derived from the Semitic `Ayin (eye), which represented a consonant, probably the voiced pharyngeal fricative (IPA: [�.]), the sound represented by the Arabic letter ع called `Ayn. This Semitic letter in its original form seems to have been inspired by a similar Egyptian hieroglyph for "eye".

The Greeks are thought to have come up with the innovation of vowel characters, and lacking a pharyngeal consonant, employed this letter as the Greek O to represent the vowel /o/, a sound it maintained in Etruscan and Latin. In Greek, a variation of the form later came to distinguish this long sound (Omega, meaning "large O") from the short o (Omicron, meaning "small o").

Its graphic form has also remained fairly constant from Phoenician times until today. Indeed, even alphabets constructed "from scratch", i.e. not derived from Semitic, usually have similar forms to represent this sound -- for example the creators of the Afaka and Ol Chiki scripts, each invented in different parts of the world in the last century, both attributed their vowels for 'O' to the shape of the mouth when making this sound.

Usage

O is most commonly associated with the close-mid back rounded vowel [o] in many languages. This form is colloquially termed the "long o" in English, but the sound used for it is actually different. In the British prestigious dialect called Received Pronunciation, the diphthong (əʊ) appears. This pronunciation and its spelling sometimes appears in British attempts to describe the French pronunciation of the letter ([o] above); North Americans use [o] for this purpose, whereas the sound they use is really the diphthong: /oʊ/.

In English there is also a "short O", which also has several pronunciations. Received pronunciation uses O to represent an open back rounded vowel (ɒ). The standard pronunciation of the stressed form of this letter in parts of North America is the open-mid back rounded vowel (ɔ). When the vowel is unstressed, its pronunciation often drops back to an open front unrounded vowel (a). The Russian language has a similar unstressed form for its equivalent letter O, which looks the same.

Common digraphs include OO, which represents either /ʊ/ or /u/; OI which typically represents the diphthong /ɔɪ/; and OA, OE, and OU represent a variety of pronunciations depending on context and etymology.

Other languages use O for various values, usually back vowels which are at least partly open. Derived letters such as Ö and Ø have been created for the alphabets of some languages to distinguish values that were not present in Latin and Greek, particularly rounded front vowels.

In the International Phonetic Alphabet, [o] represents the close-mid back rounded vowel.

Codes for computing

Alternative representations of O

NATO phonetic		Morse code
Oscar		–––
Signal flag	Semaphore	ASL Manual	Braille

In Unicode the capital O is codepoint U+004F and the lowercase o is U+006F.

The ASCII code for capital O is 79 and for lowercase o is 111; or in binary 01001111 and 01101111, correspondingly.

The EBCDIC code for capital O is 214 and for lowercase o is 150.

The numeric character references in HTML and XML are "O" and "o" for upper and lower case respectively.

Distinguishing O from zero

See 0: Distinguishing zero from O

Meanings of O

See O (disambiguation).

Similar letters and symbols

• 0 (zero)
• Oh
• ò o grave (0x00F2)
• ó o acute (0x00F3)
• ô o circumflex (0x00F4)
• õ o tilde (0x00F5)
• ö o diaeresis (0x00F6)
• ø o stroke (0x00F8)
• ō o macron (0x014D)
• ŏ o breve (0x014F)
• ő o double acute (0x0151)
• œ oe ligature (0x0153)
• ơ o horn (0x01A1)
• ǒ o caron (0x01D2)
• ǫ o ogonek (0x01EB)
• ǭ o ogonek macron (0x01ED)
• ǿ o stroke acute (0x01FF)
• ȍ o double grave (0x020D)
• ȏ o inverted breve (0x020F)
• ȫ o diaeresis macron (0x022B)
• ȭ o tilde macron (0x022D)
• ȯ o dot above (0x022F)
• ȱ o dot above and macron (0x0231)
• ṍ o tilde acute (0x1E4D)
• ṏ o tilde diaeresis (0x1E4F)
• ṑ o macron grave (0x1E51)
• ṓ o macron acute (0x1E53)
• ọ o dot below (0x1ECD)
• ỏ o hook above (0x1ECF)
• ố o circumflex acute (0x1ED1)
• ồ o circumflex grave (0x1ED3)
• �. o circumflex hook above (0x1ED5)
• ỗ o circumflex tilde (0x1ED7)
• ộ o circumflex dot below (0x1ED9)
• ớ o horn acute (0x1EDB)
• ờ o horn grave (0x1EDD)
• ở o horn hook above (0x1EDF)
• ỡ o horn tilde (0x1EE1)
• ợ o horn dot below (0x1EE3)
• ɵ o bar (0x0275)
• ο Greek omicron (0x03BF)
• о Cyrillic o (0x043E)

See also

Wikimedia Commons has media related to:

O