⟨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. However, ⟨a⟩ occurs in many common digraphs, all with their own sound or sounds, particularly ⟨ai⟩, ⟨au⟩, ⟨aw⟩, ⟨ay⟩, ⟨ea⟩ and ⟨oa⟩. There are some other cases aside from italic type where script a ⟨ɑ⟩, also called Latin alpha, is used in contrast with Latin ⟨a⟩, such as in the International Phonetic Alphabet. The Roman form ⟨a⟩ is found in most printed material, and consists of a small loop with an arc over it. In the hands of medieval Irish and English writers, this form gradually developed from a 5th-century form resembling the Greek letter tau ⟨τ⟩.
In English, ⟨a⟩ is the indefinite article (with the alternative form an when followed by a vowel). When the Romans adopted the Etruscan alphabet to write Latin, the resulting form used in the Latin script would come to be used to write many other languages, including English. The Etruscans brought the Greek alphabet to the Italian Peninsula, and they left the form of alpha unchanged. However, in the later Greek alphabet it 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. In speech and writing a is used before a consonant sound. This is the sound that the letter now normally represents when the vowel is long.
When the ancient Greeks adopted the alphabet, they had no use for a letter representing a glottal stop—so they adapted the sign to represent the vowel /a/, calling the letter by the similar name alpha. The earliest known ancestor of A is aleph—the first letter of the Phoenician alphabet—where it represented a glottal stop [ʔ], as Phoenician only used consonantal letters. A, or a, is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Before a consonant sound represented by a vowel letter a is usual In the Phoenician alphabet the letter stood for a species of breathing, as vowels were not represented in the Semitic alphabets.



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