“Grave accent”的意思、由来-开放百科全书

The grave accent ( ` ) ({{IPAc-en|ɡ|r|eɪ|v}}^[1]^[2] or {{IPAc-en|ɡ|r|ɑː|v}}^[1]^[2]) is a diacritical mark in many written languages, including Breton, Catalan, Corsican, Dutch, Emilian-Romagnol, French, West Frisian, Greek (until 1982; see polytonic orthography), Haitian Creole, Italian, Ligurian, Mohawk, Occitan, Portuguese, Romansh, Sardinian, Scots Gaelic, Vietnamese, Welsh, and Yoruba.

Uses

Pitch

The grave accent first appeared in the polytonic orthography of Ancient Greek to mark a lower pitch than the high pitch of the acute accent. In modern practice, it replaces an acute accent in the last syllable of a word when that word is followed immediately by another word. The grave and circumflex have been replaced with an acute accent in the modern monotonic orthography.

The accent mark was called {{wikt-lang|grc|βαρεῖα}}, the feminine form of the adjective {{wikt-lang|grc|βαρύς}} ({{grc-transl|βαρύς}}), meaning "heavy" or "low in pitch". This was calqued (loan-translated) into Latin as {{wikt-lang|la|gravis}}, which then became the English word grave.

Stress

The grave accent marks the stressed vowels of words in Maltese, Catalan, and Italian.

A general rule in Italian is that words that end with stressed {{lang|it|-a}}, {{lang|it|-i}} or {{lang|it|-u}} must be marked with a grave accent. Words that end with stressed {{lang|it|-e}} or {{lang|it|-o}} may bear either an acute accent or a grave accent, depending on whether the final e or o sound is closed or open, respectively. Some examples of words with a final grave accent are {{lang|it|città}} ("city"), {{Lang|it|così}}("so/then/thus"), {{Lang|it|più}} ("more"/"plus"), {{lang|it|Mosè}} ("Moses"), and {{lang|it|portò}} ("[he/she/it] brought/carried"). Typists who use a keyboard without accented characters and are unfamiliar with input methods for typing accented letters sometimes use a separate grave accent or even an apostrophe instead of the proper accent character. This is nonstandard but is especially common when typing capital letters: *{{lang|it|E`}} or *{{lang|it|E’}} instead of {{lang|it|È}} ("[he/she/it] is"). Other mistakes arise from the misunderstanding of truncated and elided words: the phrase {{lang|it|un po’}} ("a little"), which is the truncated version of {{lang|it|un poco}}, may be mistakenly spelled as *{{lang|it|un pò}}. Italian has word pairs where one has an accent marked and the other not, with different pronunciation and meaning—such as {{lang|it|pero}} ("pear tree") and {{lang|it|però}} ("but"), and {{lang|it|Papa}} ("Pope") and {{lang|it|papà}} ("dad"); the last example is also valid for Catalan.

In Bulgarian, the grave accent sometimes appears on the vowels {{lang|bg|а}}, {{lang|bg|о}}, {{lang|bg|у}}, {{lang|bg|е}}, {{lang|bg|и}}, and {{lang|bg|ъ}} to mark stress. It most commonly appears in books for children or foreigners, and dictionaries—or to distinguish between near-homophones: {{lang|bg|па̀ра}} ({{lang|bg-Latn|pàra}}, "steam/vapour") and {{lang|bg|пара̀}} ({{lang|bg-Latn|parà}}, "cent/penny, money"), {{lang|bg|въ̀лна}} ({{lang|bg-Latn|bằlna}}, "wool") and {{lang|bg|вълна̀}} ({{lang|bg-Latn|bǎlnà}}, "wave").

In Macedonian the stress mark is orthographically required to distinguish homographs (see Disambiguation) and is put mostly on the vowels е and и. Then, it forces the stress on the accented word-syllable instead of having a different syllable in the stress group getting accented. In turn, it changes the pronunciation and the whole meaning of the group.

Ukrainian, Rusyn, Belarusian, and Russian used a similar system until the first half of the 20th century. Now the main stress is preferably marked with an acute, and the role of the grave is limited to marking secondary stress in compound words (in dictionaries and linguistic literature).

In Serbo-Croatian and in Slovene, the stressed syllable can be short or long and have a rising or falling tone. They use (in dictionaries, orthography, and grammar books, for example) four different stress marks (grave, acute, double grave, and inverted breve). The system is identical both in Latin and Cyrillic scripts.

In modern Church Slavonic, there are three stress marks (acute, grave, and circumflex), which formerly represented different types of pitch accent. There is no longer any phonetic distinction between them, only an orthographical one. The grave is typically used when the stressed vowel is the last letter of a multiletter word.

In Ligurian, the grave accent marks the accented short vowel of a word in {{lang|lij|à}} (sound {{IPA|[a]}}), {{lang|lij|è}} (sound {{IPA|[ɛ]}}), {{lang|lij|ì}} (sound {{IPA|[i]}}) and {{lang|lij|ù}} (sound {{IPA|[y]}}). For {{lang|lij|ò}}, it indicates the short sound of {{IPA|[o]}}, but may not be the stressed vowel of the word.{{citation needed|date=May 2013}}

Height

The grave accent marks the height or openness of the vowels e and o, indicating that they are pronounced open: è {{IPA|[ɛ]}} (as opposed to é {{IPA|[e]}}); ò {{IPA|[ɔ]}} (as opposed to ó {{IPA|[o]}}), in several Romance languages:

Disambiguation

In several languages, the grave accent distinguishes both homophones and words that otherwise would be homographs:

Length

In Welsh, the accent denotes a short vowel sound in a word that would otherwise be pronounced with a long vowel sound: {{lang|cy|mẁg}} {{IPA-all|mʊɡ|}} "mug" versus {{lang|cy|mwg}} {{IPA-all|muːɡ|}} "smoke".

In Scottish Gaelic, it denotes a long vowel, such as {{lang|gd|cùis}} {{IPA-all|kʰuːʃ|}} ("subject"), compared with {{lang|gd|cuir}} {{IPA-all|kʰuɾʲ|}} ("put"). The use of acute accents to denote the rarer close long vowels, leaving the grave accents for the open long ones, is seen in older texts, but it is no longer allowed according to the new orthographical conventions.

Tone

In some tonal languages such as Vietnamese, and Mandarin Chinese (when it is written in Hanyu Pinyin or Zhuyin Fuhao), the grave accent indicates a falling tone. The alternative to the grave accent in Mandarin is the numeral 4 after the syllable: pà = pa4.

In African languages, the grave accent often indicates a low tone: Nobiin jàkkàr ("fish-hook"), Yoruba àgbọ̀n ("chin"), Hausa màcè ("woman").

Other uses

In Emilian-Romagnol, a grave accent placed over e or o denotes both length and openness. In Emilian è and ò represent {{Ipa|[ɛː]}} and {{IPA|[ɔː]}}, while in Romagnol they represent {{Ipa|[ɛ]}} and {{IPA|[ɔ]}}.

In Portuguese, the grave accent indicates the contraction of two consecutive vowels in adjacent words (crasis). For example, instead of a aquela hora ("at that hour"), one says and writes àquela hora.

In Hawaiian, the grave accent is not placed over another character but is sometimes encountered as a typographically easier substitute for the ʻokina: Hawai`i instead of Hawaiʻi.

English

The grave accent, though rare in English words, sometimes appears in poetry and song lyrics to indicate that a usually-silent vowel is pronounced to fit the rhythm or meter. Most often, it is applied to a word that ends with -ed. For instance, the word looked is usually pronounced {{IPAc-en|l|ʊ|k|t}} as a single syllable, with the e silent; when written as lookèd, the e is pronounced: {{IPAc-en|ˈ|l|ʊ|k|ɪ|d}} look-ed). In this capacity, it can also distinguish certain pairs of identically spelled words like the past tense of learn, learned {{IPAc-en|l|ɜːr|n|d}}, from the adjective learnèd {{IPAc-en|ˈ|l|ɜːr|n|ɪ|d}} (for example, "a very learnèd man").

Accents, sometimes combined with italics, are often applied to foreign terms not commonly used in or that are not fully assimilated into English: for example, vis-à-vis, pièce de résistance and crème brûlée. {{citation needed|date=February 2019}}

As surrogate of apostrophe or (opening) single quote

The layout of some European PC keyboards combined with problematic keyboard driver semantics causes many users to use a grave accent or an acute accent instead of an apostrophe when typing in English (e.g. typing Brian`s Theater or Brian´s Theater instead of Brian's Theater).^[3]

Additionally ASCII grave accent character ({{unichar|60|Grave accent}}) was often used as surrogate of opening single quote, together with ASCII typewriter apostrophe ({{unichar|27|Apostrophe}}) used as closing single quote; double quotes were sometimes substituted by two consecutive grave accents and two consecutive typewriter apostrophes (``…''). Although Unicode now provides separate characters for single and double quotes, such style is sometimes used even nowadays; examples are: output generated by some of UNIX console programs, rendering of man pages within some environments, technical documentation written long ago or written in old-school manner. However, as time goes on, such style is used less and less; and even institutions that traditionally were using that style are now abandoning it.^[4]^[5]

Technical notes

The Unicode standard makes dozens of letters with a grave accent available as precomposed characters. The older ISO-8859-1 character encoding only includes the letters à, è, ì, ò, ù, and their respective capital forms. In the much older, limited 7-bit ASCII character set, the grave accent is encoded as character 96 (hex 60). Outside the US, character 96 is often replaced by accented letters. In the French ISO 646 standard, the character at this position is µ. Many older UK computers, such as the ZX Spectrum and BBC Micro, have the £ symbol as character 96, though the British ISO 646 variant ultimately placed this symbol at position 35 instead.

On many computer keyboards, the grave accent is a key by itself. Due to the character's presence in ASCII this is primarily used to actually type that character, though some layouts{{which|date=January 2019}} may use it as a dead key to modify the following letter. On a US and UK QWERTY keyboard, the {{key press|`}} key is placed in the top left corner to the left of the {{key press|1}} key. On a Czech QWERTZ keyboard, the equivalent keystroke is usually mapped to {{key press|Alt Gr|ý}}.

On a Mac, to get a character such as à, the user can type {{key press|Option|`}} and then the vowel. For example, to make à, the user can type {{key press|Option|`}} and then {{key press|a}}, and to make À, the user can type {{key press|Option|`}} and then {{key press|Shift|a}}. In iOS and most Android keyboards, combined characters with the grave accent are accessed by holding a finger on the vowel, which opens a menu for accents. For example, to make à, the user can tap and hold {{key press|a}} and then tap or slide to {{key press|à}}. Mac versions of OS X Mountain Lion (10.8) or newer share similar functionality to iOS; by pressing and holding a vowel key to open an accent menu, the user may click on the grave accented character or type the corresponding number key displayed.

On a system running the X Window System, to get a character such as à, the user should press {{key press|Compose}} followed by {{key press|`}}, then the vowel. The compose key on modern keyboards is usually mapped to a {{key press|Win}} key or {{key press|Shift|Alt Gr}}.^[6]

Games

In many PC-based computer games in the US and UK, the {{key press|`}} key (on U.S. English and U.K. keyboards) is used to open the console so the user can execute script commands via its CLI. {{citation needed|date=February 2016}} This is true for games such as Battlefield 3, Half-Life, Halo CE, Quake, Half-Life 2, Blockland, Double Helix, Unreal, Counter-Strike, Crysis, Morrowind, Oblivion, Skyrim,^[7] New Vegas, Fallout 3, Fallout 4, RuneScape, and others based on the Quake engine or Source engine. {{citation needed|date=February 2016}}

It is sometimes used in roguelike games to represent water or snakes. {{citation needed|date=February 2016}}

Use in programming

Programmers use the grave accent symbol as a separate character (i.e., not combined with any letter) for a number of tasks. In this role, it is known as a backquote, backgrave, or backtick.

When using TeX to typeset text, the backtick character represents curly opening quotes. For example, ` is rendered as single opening curly quote ({{not a typo|‘}}) and `` is a double curly opening quote ({{not a typo|“}}). It also supplies the numeric ASCII value of an ASCII character wherever a number is expected.

Many of the Unix shells and the programming languages Perl, PHP, and Ruby use pairs of this character to indicate command substitution, that is, substitution of the standard output from one command into a line of text defining another command. For example, the code line:

This is also the format the Markdown formatter uses to indicate code.^[8] Some variations of Markdown support "fenced code blocks" that span multiple lines of code, starting (and ending) with three backticks in a row (```).^[9]

let nursery = ˋAnd so ${name} had a little ${pet} whose external covering is of a color not determined by this scriptˋ;