Letter Case

In orthography and typography, letter case (or just case) is the distinction between the larger upper case (capital letters, caps, majuscule, upper-case, or uppercase) and smaller lower-case (minuscule, etc.) letters in certain languages. The term originated with the shallow drawers called type cases still used to hold the movable type for letterpress printing.

In the Latin script, capital letters are A, B, C, etc.; lower case includes a, b, c, etc.

Most Western languages (certainly those based on the Latin, Cyrillic, Greek, Armenian alphabets, and Coptic alphabets) use multiple letter-cases in their written form as an aid to clarity. Scripts using two separate cases are also called "bicameral scripts". Many other writing systems (such as those used in the Georgian language, Glagolitic, Arabic, Hebrew, and Devanagari) make no distinction between capital and lowercase letters – a system called unicase. If an alphabet has case, all or nearly all letters have both forms. Both forms in each pair are considered to be the same letter: they have the same name and pronunciation and will be treated identically when sorting in alphabetical order. An example of a letter without both forms is the German ß (ess-tsett), which exists only in minuscule. When capitalized it normally becomes two letters ("SS"), but the ß letter may be used as a capital to prevent confusion in special cases, such as names. This is because ß was originally a ligature of the two letters "ſs" (a long s and an s), both of which become "S" when capitalized. It later evolved into a letter in its own right. (ß is also occasionally referred to as a ligature of "sz", which recalls the way this consonant was pronounced in some medieval German dialects. The original spelling sz is preserved in Hungarian and pronounced .)

Languages have capitalization rules to determine whether upper case or lower case letters are to be used in a given context. In English, capital letters are used as the first letter of a sentence, a proper noun, or a proper adjective, and for initials or abbreviations in American English; British English only capitalizes the first letter of an abbreviation. The first-person pronoun "I" and the interjection "O" are also capitalized. Lower-case letters are normally used for all other purposes. There are however situations where further capitalization may be used to give added emphasis, for example in headings and titles or to pick out certain words (often using small capitals). There are also a few pairs of words of different meanings whose only difference is capitalization of the first letter. Other languages vary in their use of capitals. For example, in German the first letter of all nouns is capitalized, while in Romance languages the names of days of the week, months of the year, and adjectives of nationality, religion and so on generally begin with a lower-case letter.