A

A, ora, is the firstletterand the firstvowel letterof theLatin alphabet,used in the modernEnglish alphabet, and others worldwide. Its name in English isa(pronounced/ˈeɪ/AY), pluralaes.
It is similar in shape to theAncient Greekletteralpha, from which it derives.Theuppercaseversion consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version is often written in one of two forms: the double-storey|a|and single-storey|ɑ|. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found initalic type.
In English,ais theindefinite article, with the
alternative forman.
In English, the name of the letter is thelong Asound, pronounced/ˈeɪ/. Its name in most other languages matches the letter's pronunciation inopen syllables.
The earliest known ancestor of A isaleph—the first letter of thePhoenician alphabet—where it represented aglottal stop[ʔ], as Phoenician only usedconsonantalletters. In turn, the ancestor of aleph may have been apictogramof an ox head inproto-Sinaitic scriptinfluenced byEgyptian hieroglyphs, styled as a triangular head with two horns extended.
When theancient Greeksadopted the alphabet, they had no use for a letter representing aglottal stop—so they adapted sign to represent the vowel/a/, calling the letter by the similar namealpha. In the earliest Greek inscriptions dating to the 8th century BC following theGreek Dark Ages, the letter rests upon its side. However, in the laterGreek alphabetit generally resembles the modern capital form—though many local varieties can be distinguished by the shortening of one leg, or by the angle at which the cross line is set.
TheEtruscansbrought the Greek alphabet to theItalian Peninsula, and left the form of alpha unchanged. When the Romans adopted theEtruscan alphabetto writeLatin, the resulting form used in theLatin scriptwould come to be used to write many  other languages, including English.
During Roman times, there were many variant forms of the letter A. First was the monumental or lapidary style, which was used when inscribing on stone or other more permanent media. There was also acursivestyle used for everyday or utilitarian writing, which was done on more perishable surfaces. Due to the perishable nature of these surfaces, there are not as many examples of this style as there are of the monumental, but there are still many surviving examples of different types of cursive, such asmajusculecursive,minusculecursive, and semi-cursive minuscule. Variants also existed that were intermediate between the monumental and cursive styles. The known variants include the earlysemi-uncial, the uncial, and the later semi-uncial.
At the end of theRoman Empire(5th century AD), several variants of the cursive minuscule developed through Western Europe. Among these were the semi-cursive minuscule of Italy, theMerovingian scriptin France, theVisigothic scriptin Spain, and theInsularor Anglo-Irish semi-uncial or Anglo-Saxon majuscule of Great Britain. By the ninth century, theCaroline script, which was very similar to the present-day form, was the principal form used in book-making, before the advent of the printing press. This form was derived through a combining of prior forms.
15th-century Italy saw the formation of the two main variants that are known today. These variants, theItalicandRomanforms, were derived from the Caroline Script version. The Italic form⟨ɑ⟩, also calledscript a, is often used inhandwriting; it consists of a circle with a vertical stroke on its right. In the hands of medieval Irish and English writers, this form gradually developed from a 5th-century form resembling the Greek lettertau⟨τ⟩.The Roman form⟨a⟩is found in most printed material, and consists of a small loop with an arc over it.Both derive from the majuscule form⟨A⟩. In Greek handwriting, it was common to join the left leg and horizontal stroke into a single loop, as demonstrated by the uncial version shown. Many fonts then made the right leg vertical. In some of these, theserifthat began the right leg stroke developed into an arc, resulting in the printed form, while in others it was dropped, resulting in the modern handwritten form. Graphic designers refer to theItalicandRomanforms assingle-decker aanddouble decker arespectively.
Italic typeis commonly used to mark emphasis or more generally to distinguish one part of a text from the rest set in Roman type. There are some other cases aside from italic type wherescript a⟨ɑ⟩, also calledLatin alpha, is used in contrast with Latin⟨a⟩, such as in theInternational Phonetic Alphabet.
In modernEnglish orthography, the letter⟨a⟩represents at least seven different vowel sounds, here represented using the vowels ofReceived Pronunciation, witheffects of⟨r⟩ignored and mergers inGeneral Americanmentioned where relevant:
The double⟨aa⟩sequence does not occur in native English words, but is found in some words derived from foreign languages such asAaronandaardvark.However,⟨a⟩occurs inmany common digraphs, all with their own sound or sounds, particularly⟨ai⟩,⟨au⟩,⟨aw⟩,⟨ay⟩,⟨ea⟩and⟨oa⟩.
⟨a⟩is the third-most-commonly used letter in English after⟨e⟩and⟨t⟩, as well as in French; it is the second most common in Spanish, and the most common in Portuguese.⟨a⟩represents approximately 8.2% of letters as used in English texts;the figure is around 7.6% in French11.5% in Spanish,and 14.6% in Portuguese.
In most languages that use the Latin alphabet,⟨a⟩denotes an open unrounded vowel, such as/a/,/ä/, or/ɑ/. An exception isSaanich, in which⟨a⟩—and the glyph⟨Á⟩—stands for aclose-mid front unrounded vowel/e/.
The Latin letters⟨A⟩and⟨a⟩haveUnicodeencodingsU+0041ALATIN CAPITAL LETTER AandU+0061aLATIN SMALL LETTER A. These are the samecode pointsas those used inASCIIandISO 8859. There are alsoprecomposed characterencodings for⟨A⟩and⟨a⟩with diacritics, for most of those listedabove; the remainder are produced usingcombining diacritics.
Variant forms of the letter have unique code points for specialist use: thealphanumeric symbols setin mathematics and science,Latin alphain linguistics, andhalfwidth and fullwidth formsfor legacyCJKfont compatibility. The Cyrillic and Greekhomoglyphsof the Latin⟨A⟩have separate encodingsU+0410АCYRILLIC CAPITAL LETTER AandU+0391ΑGREEK CAPITAL LETTER ALPHA.