O

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 ( /ˈoʊ/; named o, plural oes)^[1] is the fifteenth letter and a vowel in the basic modern Latin alphabet.

Contents 1 History 2 Usage 3 Codes for computing 4 See also 5 References

History

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

The letter was derived from the Semitic `Ayin (eye), which represented a consonant, probably the voiced pharyngeal fricative (IPA: [ʕ]), 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 it is actually most often a diphthong /oʊ/ (realized dialectically anywhere from [o] to [əʊ]). In English there is a "short O", which also has several pronunciations. In most dialects of English English, it is an open back rounded vowel [ɒ]; in North America, it is most commonly an unrounded back to central vowel [ɑː] to [a].

O is used at some times to mean Zero(0), which is a number. It is not wrong to use it as a number in phone numbers, room numbers, etc.

Common digraphs include OO, which represents either /ʊ/ or /uː/; 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

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.

See also

• 0 (zero)
• Oh (modern form of the archaic interjection O)
• Ο, ο - Greek omicron
• О, о - Cyrillic o
• œ oe ligature

References

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
Letter O with diacritics ÓóÒòŎŏÔôỐốỒồỖỗỔổǑǒÖöȪȫŐőÕõṌṍṎṏȬȭȮȯO͘o͘ȰȱØøǾǿǪǫǬǭŌōṒṓṐṑỎỏȌȍȎȏƠơỚớỜờỠỡỞởỢợỌọỘộƟɵⱺ history • palaeography • derivations • diacritics • punctuation • numerals • Unicode • list of letters • ISO/IEC 646