A

A is the first letter of the English alphabet. The small letter, a, is used as a lowercase vowel.^[1]

When it is spoken, ā is said as a long a, a diphthong of ĕ and y. A is similar to Alpha of the Greek alphabet. That is not surprising, because it means the same sound. "Alpha and Omega" (the last letter of the Greek alphabet) means from beginning to the end. In musical notation, the letter A is the symbol of a note in the scale, below B and above G.

A is the letter that was used to represent a team in an old TV show, The A-Team. A capital a is written "A". Use a capital A at the start of a sentence if writing. A is also a musical note, sometimes referred to as "La".

The letter 'A' was in the Phoenician alphabet's aleph.^[2] This symbol came from a simple picture of an ox head.

Egyptian	Phoenician aleph	Greek Alpha	Etruscan A	Roman/Cyrillic A

This Phoenician letter helped make the basic blocks of later types of the letter. The Greeks later modified this letter and used it as their letter alpha. The Greek alphabet was used by the Etruscans in northern Italy, and the Romans later modified the Etruscan alphabet for their own language.

The letter A has six different sounds. It can sound like æ, in the International Phonetic Alphabet, such as the word pad. Other sounds of this letter are in the words father, which developed into another sound, such as in the word ace.

In algebra, the letter "A" along with other letters at the beginning of the alphabet is used to represent known quantities.

In geometry, capital A, B, C etc. are used to label line segments, lines, etc. Also, A is typically used as one of the letters to label an angle in a triangle.

Its letter shape is referred to abstractly in Sir William Vallance Douglas Hodge's 5th postulate, the basis for, as one of the Millennium Prize Problems, the Hodge Conjecture.

The Simple English Wiktionary has a definition for: a.

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