In writing and typography, a ligature occurs where two or more letterforms are written or printed as a unit. Generally, ligatures replace characters that occur next to each other when they share common components. A letter with an accent mark is not usually called a ligature, though it would require a separate block of type just as a ligature does. Ligatures are a subset of a more general class of figures called "contextual forms", where the particular shape of a letter depends upon its context, such as surrounding letters or whether or not it appears at the end of a line.
The Family of Ligatures for the Letter f
One of the most common ligatures recognizeable as such is "fi." Since the dot above a lowercase i interferes with the loop on the lowercase f, when "f" and "i" are printed next to each other, they are combined into a single figure with the dot absorbed into the "f," which appears as "ﬁ". This is just one of a series, which comprises ligatures for "fi", "fj" (absent in English but encountered in Esperanto, Norwegian, and other languages where j represents a vocalic or semi-vocalic sound), "fl", "ff", "ffi", and "ffl". Formerly there were the additional members for "fa", "fe", "fo", "fr", "fs", "ft", "fu", "fy", and for the set of "f" followed by a period (full stop), comma, or hyphen, as well as the equivalent set for the doubled "ff", though "fft" was omitted.
The Double "Vee"
As the letter W is not in the Latin alphabet, the sound was originally written in various ways. In Old English the Runic letter Wynn (Ƿ) was used, but Norman influence forced this character out. Later, two Vs or Us were written together. As seen in old typefaces, originally the two "V's" crossed in the middle. Hence VV developed into W, but the modern Latin letter W is not a true ligature, as it represents a different sound from VV/UU.
Perhaps the most common ligature is the ampersand: "&". This was originally a ligature of 'Et', Latin for 'and'. It has exactly the same use, except for pronunciation, in French, and is used in the English language just as in French. This character comes in many different forms.
Ligature or Independent Letter?
It is important to note that the character Æ (æ) when used in the Danish, Norwegian languages or Old English is not a typographical ligature and must never be treated as such. It is a distinct letter and vowel, and keeps its place in the different alphabetic sequence of those languages, rather than coming between "ad" and "af".
This character derives from its use in Latin. But it is not required in that language; works appear either with it or, as is currently popular, with the two component letters separated. Hence in Latin, and when Latin names are written with it in French and Modern English text, it is considered a ligature. Similarly, the character Œ (œ) can be used in French, or can be replaced by its component letters by technical restrictions, so it is a ligature for that language as well.
Characters that will not appear in English or French include the letter ß, which was derived from the ligature "long s over round s". It has become a distinct letter in German, although it never begins a word (it can alternatively be spelled "ss"). The letter ĳ is derived from "II", and has similarly a distinct letter in Dutch. There is also a digraph which in Welsh would be a letter, but which is not in most lists of accessible characters, the "Ll".
More ligatures were developed for italic fonts rather than Roman ones. Fonts in italics used the "Long s" in ligatures for "sh", "sch", "sp", "st" and "sz", among others mentioned on this page. There are also examples for the forms "as", "ch", "ck", "nd", "ng", and "ll". And there is one to make the tail for "Q" reach under a "u", though this was also done by kerning or a character for "u" that included a tail sweep beneath it.
One Roman font by the French typefounder Garamond has a small capital ligature "Rx" for use in prescriptions, short for the Latin word "recipe", meaning "take". The same font has a minuscule "l" linked to a following apostrophe, for use in such French phrases such as "l'amour".
The cursive Snell Roundhand has a ligature "o'c" for the single use in the English phrase "o'clock", as its letter "o" has an extended flourish. For use in ordinal numerals in English, the font has raised small minuscules for "nd", "rd", "st", and "th".
A Roman typeface by William Elder had a distinct "ll". He decorated the second "l" with two nibs at mean line height, and put it in a ligature so as to not get it confused with an ordinary "l", to which he gave just one.
Zuzana Licko's Mrs Eaves has a wide range of ligatures, including "cky", "gi", "gy" and "tty" in the italic. Some unusual combinations are found in Jack Yan's JY Integrity from 1995, including "gr", "gy", "tr", "tu" and "ty" in roman and italic versions. Stylistic ligatures may become more common with the development of the OpenType technology, which allows automatic substitution of two separately typed letters in certain programs such as Adobe InDesign CS.
Some typefaces primarily intended for signage include ligatures for the minor words in phrasal names of various languages. Examples include "and," "und," "of," "de," "for," and "het," in some presentations of FF Golden Gate Gothic. These ligatures are underlined, tilted, and float above the typographical baseline; they serve to offset major words for this otherwise all-capital typeface.
Kerning as an Alternative
A ligature is not the only way of changing the appearance on the page. Besides allocating a particular arrangement as a ligature, the relative location of the characters can be altered by kerning, something which has become easier with phototypesetting, and above all, with computer typography . The fonts for the Macintosh computer include a "dotless 'i'", which (aside from its necessity in printing Turkish) facilitates kerning "fi" and "Ti" instead of using a ligature.
History in Western Languages
Medieval scribes, writing in Latin, conserved space and increased writing speed by combining characters. For example, in blackletter, letters with right-facing bowls ("b", "o", and "p") and those with left-facing bowls ("c", "e", "o", and "q") would be written with the facing edges of the bowls superimposed. And in many forms of script, characters such as "h," "m", and "n" would have their vertical strokes superimposed. Scribes also added special marks called "scribal abbreviations " to get rid of having to write a whole character "at a stroke". Manuscripts in the fourteenth century, for example, would employ hundreds of such abbreviatons.
When printing was invented, typefaces included many of these, now physical blocks of type called ligatures. This was done not only because cheap paper had not yet been invented, but also in order to emulate the appearance of hand-lettered manuscripts. To do otherwise would have seemed to the readers as being talked down to, as a modern adult would feel when reading: "Ro·ver falls in·to the emp·ty per·am·bu·la·tor." In addition, ligatures were devised to enable typesetters to assemble Latin words quickly: the endings "us" and "is", and "ij" as a stylish medieval form of "ii" were made ligatures, too. There had been no need for special flourishes of the pen for these.
After printing was extended to modern languages, which didn't use scribal abbreviations, and as typesetting became more perfunctory, most of the earlier ligatures fell out of use, even for texts in Latin. One of the very last of these to remain resembled "q3". It had been used for the Latin ending "-que", being something like a postfix ampersand.
However, new ones were added by typefounders for the English language. The standard ones which remain are the "f" series listed above. Another series, quite resembling these, which used the "long s" in place of the "f", disappeared in the nineteenth century. In the 1920s, some Roman fonts were still being designed with special ligatures for "ct" and "st", ligatures which remain in many italic typefaces, some of which even have one for "sp". (The last two do not use the "long s".) And in the twentieth century, for the single word "fjord", which has entered the English language from Norwegian, the ligature "fj" has come into existence.
It is only recently that computer-based typesetting has encouraged people to start using ligatures again (although "fine art" printers have used them all along). Generally, ligatures work best in typefaces which are derived from calligraphic letterforms. Also useful are contextual forms, such as swash capitals , terminal characters, and so on.
Ligatures in Other Alphabets
Ligatures are not limited to Latin script. Some forms of the Glagolitic script, used from Middle Ages to the 19th century to write some Slavic languages, have a "boxy" shape that leads to a more frequent use of ligatures. And in the Arabic alphabet, which has a very "fluid" shape, there is usually ligature between every single letter.
A number of ligatures have been employed with the Greek alphabet, in particular a ligature of omicron (Ο) and upsilon (Υ) which later gave rise to one of the letters of the Cyrillic alphabet. Several other letters of the Cyrillic alphabet were originally ligatures but are now considered to be single letters.
An example of a more general contextual form is the Greek lowercase sigma. When typesetting Greek, the selection of which sigma to use is determined by whether or not the letter occurs at the end of the word. From these particulars derived the rules for the "long s" in Western languages formerly.
Specialized Computer Typesetting Programs
Typical ligatures in Latin script
TeX is an example of a computer typesetting system that makes use of ligatures automatically. The Computer Modern Roman typeface, which is provided with TeX, includes the five common ligatures ff, fi, fl, ffi, and ffl. When TeX finds these letters juxtaposed in the text, it substitutes the appropriate ligature (unless overridden by the typesetter). Some believe that the writer should be able to decide whether to use a ligature or not; others that it is the job of a typesetter.
This table shows unligatured sets of letters on the left, the corresponding Unicode ligature in the middle column, and the Unicode code points on the right. Provided you are using an operating system and user agent that can handle Unicode, and have the correct Unicode fonts installed, some or all of these will display correctly. See also the provided graphic.
|ſs (or ſz)
This is a list of ligatures with articles:
Danish, Norwegian and German alphabet.