A or a is the first letter and vowel of modern English letters and ISO Basic Latin letters. Its English name is a, plural AES. Its shape is similar to the ancient Greek letter alpha from which it originated. The upper case version consists of two slashes of a triangle intersected by a horizontal bar. The lowercase version can be written in two forms: double-layer A and single-layer a. The latter is commonly used for handwritten and handwriting based fonts, especially those intended for children's reading, and also appears in italics.

In English grammar, "a" and its variant "an" are indefinite articles.

In Roman times, the letter "a" had many variations. The first is a monumental or monotonous style, used to carve in stone or other "permanent" media. There is also a cursive style for everyday or utilitarian writing, which is done on a more perishable surface. Due to the "perishable" nature of these surfaces, there are not as many examples of this style as commemorative ones, but there are still many remaining examples of different types of cursive script, such as shanzhucao, xiaocaoshu and semi cursive script. Small. There are also variations between monumental and cursive styles. Known variants include early, unofficial, and later semiofficial.

Printing variants include double-layer A and single-layer a.

At the end of the Roman Empire (5th century A.D.), several varieties of cursive script developed throughout Western Europe. Among them are Italian cymbic lowercase, French Merlot, Spanish Visigothic, and English insular or Anglo Irish or Anglo Saxon majuscule. By the 9th century, before the advent of today's printing press, Caroline characters, which are very similar to today's forms, were the main form of book making. This table is obtained by merging the previous tables.

Italy in the 15th century witnessed the formation of two major variants known today. These variants (italics and Roman) are derived from the Caroline script version. The italicized form, also known as script a, is used in most current strokes and consists of circles and vertical strokes. It began to develop slowly in the fifth century, similar to the Greek letter tau in the hands of Irish and British writers in the middle ages. Most printing materials are in Roman form. It consists of a small ring with an arc ("a") on it. Both come from the form of powerlessness. In Greek handwriting, the left leg and horizontal strokes are usually connected in a loop, as shown in the unofficial version. Then, many fonts make the right leg vertical. In some cases, the liner that starts the right leg stroke develops into an arc, forming a printed form, while in other cases, it drops, forming a modern handwritten form.

Italics are often used to mark emphasis, or more generally to separate parts of the text from the rest (set in Roman font). In addition to the italics, there are other cases where the script a ("or"), also known as the Latin alphabet alpha, is used in comparison to the Latin "a" (for example, the international phonetic alphabet).