question mark

The question mark (?), also known as an interrogation point, question point, query,^[1] or eroteme, is a punctuation mark that replaces the period at the end of an interrogative sentence. It can also be used mid-sentence to mark a merely interrogative phrase, where it functions similarly to a comma, such as in the single sentence "Where shall we go? and what shall we do?", but this usage is increasingly rare. The question mark is not used for indirect questions. The question mark character is also often used in place of missing or unknown data.

Standard question mark

History

Lynne Truss attributes an early form of the question mark to Alcuin of York.^[2] Truss describes the punctus interrogativus of the late 700s as "a lightning flash, striking from right to left", a mark looking like this. The punctuation system of Aelius Donatus, current through the Early Middle Ages, used only simple dots at various heights. This early question mark was a decoration of one of these dots, with the "lightning flash" perhaps meant to denote intonation, and perhaps associated with early musical notation like neumes^[3][4].

The symbol is also sometimes ^[5] thought to originate from the Latin quaestiō (that is, qvaestio), meaning "question", which was abbreviated during the Middle Ages to Qo. The uppercase Q was written above the lowercase o, and this mark was transformed into the modern symbol.

The name "question mark" was coined in the late 1800s by Lee Coleman.^[6]

Other languages

Opening (inverted) and closing question marks for Spanish-language questions

In some languages, such as Spanish, Galician and Leonese, typography since the 18th century has required opening and closing question marks, as in "¿Qué hora es?" (What time is it?); an interrogative sentence or phrase begins with an inverted question mark (¿) and ends with the question mark (?). This orthographical rule is often disregarded in quick typing, although its omission is always considered a mistake. In Greek and Church Slavonic, a semicolon (;) is used as a question mark.

Question mark in Armenian

In Armenian the question mark (՞ ) has a form of an open circle and is placed over the last vowel of the question word.

In Arabic and Persian, which are written from right to left, the question mark "؟" is mirrored right-to-left from the English question mark. (Some browsers may display the character in the previous sentence as a forward question mark due to font or text directionality issues.) Hebrew is also written right-to-left, but uses a question mark that appears on the page in the same orientation as the English "?".^[7]

The question mark is also used in modern writing in Chinese, Korean, and Japanese, though it is not always required in Japanese. Usually it is written as fullwidth form (？; Unicode: U+FF1F) in Chinese and Japanese.

Rhetorical question mark

The rhetorical question mark or "percontation point" was invented by Henry Denham in the 1580s and was used at the end of a rhetorical question; however, its use died out in the 1600s. It was the reverse of an ordinary question mark, so that instead of the main opening pointing back into the sentence, it opened away from it.^[8] This character can be represented using the reversed question mark (؟) found in Unicode as U+2E2E.

Rhetorical questions in some (informal) situations can use a bracketed question mark, eg. "Oh, really(?)", for example in 888 subtitles.^[9]

Some have adapted the question mark into various irony marks, but these are very rarely seen.

The question mark can also be used as a "meta" sign to signal uncertainty regarding what precedes. It is usually put between brackets (?). The uncertainty may concern either a superficial (such as unsure spelling) or a deeper truth, (real meaning) level.

Computing

In computing, the question mark character is represented by ASCII code 63, and is located at Unicode code-point U+003F. The full-width (double-byte) equivalent, ？, is located at Unicode code point U+FF1F.

The question mark is often utilized as a wildcard character: a symbol that can be used to substitute for any other character or characters in a string. In particular "?" is used as a substitute for any one character as opposed to the asterisk, "*", which can be used as a substitute for zero or more characters in a string. The inverted question mark corresponds to Unicode code-point 191 (U+00BF), and can be accessed from the keyboard in Microsoft Windows on the default US layout by holding down the Alt key and typing either 1 6 8 (ANSI) or 0 1 9 1 (Unicode) on the numeric keypad. In GNOME applications, it can be entered by typing the hexadecimal Unicode character while holding ctrl-shift, i.e.: ctrl-shift BF - ¿. In recent XFree86 and X.Org incarnations of the X Window System, it can be accessed as a compose sequence of two straight question marks, i.e. pressing <Compose> ? ? yields ¿. In the Mac OS, option-shift-? produces an inverted question mark.

The question mark is used in ASCII renderings of the International Phonetic Alphabet, such as SAMPA in place of the glottal stop symbol, ʔ, (which resembles "?" without the dot), and corresponds to Unicode code point U+0294, Latin letter glottal stop.

In computer programming, the symbol "?" has a special meaning in many programming languages. In C-descended languages, "?" is part of the ?: operator, which is used to evaluate simple boolean conditions. In C# 2.0, the "?" modifier and the "??" operator are used to handle nullable data types. In the POSIX syntax for regular expressions, such as the one used in Perl and Python, ? stands for "zero or one instance of the previous subexpression", i.e. an optional element.

In many web browsers, "?" is used to show a character not found in the program's character set. This commonly occurs for apostrophes and quotation marks when they are written with software that uses its own proprietary non-standard code for these characters, such as Microsoft's Smart Quotes. Some fonts will instead use the Unicode Replacement Glyph (U+FFFD, �), which is commonly rendered as a white question mark in a black diamond.

The generic URL syntax allows for a query string to be appended to a resource location in a web address so that additional information can be passed to a script; the query mark, ?, is used to indicate the start of a query string. A query string is usually made up of a number of different field/value pairs, each separated by the ampersand symbol, &, as seen in this url:

http://www.example.com/login.php?username=test&password=blank

Here, a script on the page login.php on the server www.example.com is to provide a response to the query string containing the pairs "username=test" and "password=blank".

Chess

In algebraic chess notation, "?" denotes a bad move, and "??" a blunder, "?!" a dubious move and "!?" an interesting move. For details of all of the chess punctuation see punctuation (chess).

Mathematics

In mathematics "?" commonly denotes Minkowski's question mark function.

Medicine

A question mark is used in English medical notes to suggest a possible diagnosis. It facilitates the recording of a doctor’s impressions regarding a patient’s symptoms and signs. For example, for a patient presenting with left lower abdominal pain, a differential diagnosis might include ?Diverticulitis (read as 'Query Diverticulitis').

See also

• Irony point
• Exclamation mark
• Interrobang
• Quine's Question Mark

Notes

References

External links

Wikimedia Commons has media related to: Question mark

• The question mark and indirect questions