Open syllable lengthening

In linguistics, open syllable lengthening is the process by which short vowels become long when in an open syllable. It occurs in many languages at a phonetic or allophonic level, where no meaningful distinction in length is made. However, as it became phonemic in the Germanic languages, it is especially significant there, both historically and in the modern languages.

Germanic languages

Open syllable lengthening affected the stressed syllables of all Germanic languages in their history to some degree. Curiously, it seems to have affected all the languages around a similar time, somewhere between the twelfth and sixteenth centuries (the late Middle Ages). The languages mainly differ in which vowels were lengthened and in which specific environment, but also in what the result of this lengthening was. There is substantial variation and in many languages the process has been largely undone by paradigmatic leveling. Sometimes, the newly lengthened vowels merged with existing long vowels, while in other languages they remained distinct because the older long vowels underwent changes of their own (such as in Icelandic, and in the Scandinavian languages to a lesser degree).

The lengthening often also applied in reverse at some point, shortening long vowels in closed syllables. As a consequence of the combination of these two changes, vowel length and consonant length came to be in complementary distribution. Because of that, consonant length was no longer a distinctive feature, and long consonants were shortened in many languages at some point afterwards. This in turn had consequences for spelling, in which consonant length was generally marked by doubling in the various Germanic languages, but vowel length was not. The doubled consonants then came to be used as an indicator for vowel length (and later, quality), a feature seen in all Germanic languages today.

Dutch

In Dutch, the process was already underway around the twelfth century, making it one of the earliest languages to be affected. It is consistently reflected in written documents of the thirteenth century, which reflect long vowels in closed syllables by doubling the vowel or by adding e or i, but not in open syllables, showing that length had become entirely conditioned by the consonants that followed.

Besides lengthening, some vowels also differed in quality somewhat afterwards. Short /i/ was lowered to long /eː/ in open syllables, and /y/ was lengthened to /øː/. Similar changes would have likely affected /u/ as well, but it merged with /o/ in all environments, so there was no distinction in the lengthened result either. Long consonants began to be shortened a few hundred years afterwards, as they were no longer distinctive.

Modern Dutch spelling uses a combination of vowel and consonant doubling to indicate vowel length, a feature inherited directly from the tradition that began in the thirteenth century. However, because consonant length is no longer contrastive, doubled consonants are purely an orthographical device to indicate vowel length. Long vowels in closed syllables are doubled, and consonants are doubled following short vowels in open syllables even when this is not etymological.

English

Main article: Middle English phonology#Open-syllable lengthening

Vowel lengthening in English was very similar to the process in Dutch, and began only a short while later. As in Dutch, vowels were lowered when lengthened: /i/ > /eː/, /e/ > /ɛː/, /u/ > /oː/, /o/ > /ɔː/. This process was restricted in the following ways:

1. It did not occur when two or more syllables followed, due to the opposing process of trisyllabic laxing.
2. It only occasionally applied to the high vowels /i/ and /u/, e.g. OE wudu > ME /woːd/ > "wood"; OE wicu > ME /weːk/ > "week". Most instances of /i/ and /u/ remained as such, e.g. OE hnutu > NE "nut", OE riden > NE "ridden".

As in Dutch, long vowels were often written doubled in closed syllables, and they were often long in open syllables. This process applied neither as consistently nor as thoroughly as in Dutch, however. Generally, only e and o were doubled in this way. As word-final schwa began to disappear, the newly created silent e was added to the end of the words in which it was not etymologically justified, as a way of indicating vowel length.

The lengthening still survives in Modern English, and accounts, for example, for the vowel difference between "staff" and the alternative plural "staves" (Middle English staf vs. stāves, with open-syllable lengthening in the latter word). The effects of open-syllable lengthening and trisyllabic laxing often led to differences in the stem vowel between singular and plural/genitive. Generally these differences were regularized by analogy in one direction or another, but not in a consistent way:

• ME path, pāthes > NE "path, paths", but ME whal, whāles > NE "whale, whales"
• ME crādel, cradeles > NE "cradle, cradles", but ME sādel, sadeles > NE "saddle, saddles"

German

Vowel lengthening in German is generally thought to have occurred somewhat later, further towards the end of the Middle Ages. As a feature it probably spread north and south from the Netherlands and northern Germany, taking a century or two to reach High German. The process itself has remained much the same, however, as in Dutch.

Because the process did not begin until scribal traditions were already in place, spelling was generally not adapted to the change in length, and long vowels continued to be written as single vowels. As a result, the following consonants alone were taken to indicate length, but this was not always consistent. Substantial levelling also occurred in noun and verb paradigms, with the short-vowel forms with no ending generally adopting the long vowel of the forms with an ending by analogy.