Old Frisian
phonology has been reconstructed by analyzing the existing corpora and the language's modern descendants. In general, Old Frisian scribes used a largely
phonemic orthography, where each letter signifies a distinct phoneme. With limited exceptions,
stress fell on the stem, the base form of the word to which affixes may be added, in Old Frisian.
Vowels No distinction was made orthographically in early Old Frisian to provide for
vowel length, though in later forms of the language an or was placed after the vowel to indicate a long vowel, as in (, ). The vowel may have been a
marginal phoneme, where it is found in one extant manuscript as a
reflex of the same Proto–West Germanic phoneme, though inclusion of is based on very little evidence. The language had two
diphthongs: and , the latter of which was interchangeable with . The long vowel in is assumed from attestations in Old West Frisian, but it is unclear if it was long in earlier forms of the language, as the vowel length is unclear in the older Old East Frisian manuscripts. In later Old West Frisian, the traditional developed into , usually written as . While there were rising diphthong short forms in , no short is attested. Other marginal diphthongs existed too. For example, was common in loanwords, as in ('emperor') from Old High German, though it existed in some native terms such as . Later developments include , as in ('
flail'). Two consecutive vowels did not always form a diphthong. For example, ('enemy') has a syllable break between the first vowel and the second.
Consonants Gemination, or the long pronunciation of consonants, was possible for most consonants in word-medial position, though
semivowels (i.e., and ), voiced
allophones of voiceless fricatives typically found between vowels (i.e., , , , and ), and the alveolar affricates are exceptions.
Dirk Boutkan argues that is an exception as well, but Bremmer includes it. In earlier orthographies, geminate consonants were consistently written with duplicated consonants unless they were found in word-final position; later, the duplication only signified that the previous vowel was short. The phoneme was typically pronounced at the beginning of a syllable as if the syllable was stressed and the phoneme occurred before a vowel, , , or . It is possible that , , or clusters were realized as the voiceless allophones , , or , respectively, given that the orthography sometimes swaps them; for example, and are both attested for the same sequence. If true, Old Frisian is unique in its preservation of this voiceless quality among other contemporary Germanic languages. In all other cases, is believed to have been pronounced. The phoneme was devoiced and spirantized in word-final position; in other words, it became as well.
Orthographic conventions The
dental fricatives and were both written as , irrespective of voicing; the phoneme was sometimes written as , but no pronunciation change is thought to have occurred, however. Similarly, the cluster is sometimes written as , but it was still likely pronounced as . Though was often pronounced , could represent either or , though is vastly less common except in loans from
Medieval Latin, where it could also represent , especially word-initially or before . Instead, almost always represents either or its geminate equivalent. The insertion of was probably imported from orthographic conventions common among
Middle Low German scribes, though it is relatively rare and found primarily in Latin loans. The
digraph was often used to represent , the fricative allophone of or voiced allophone of , but could represent as well. The semivowel could be variously represented as , , , or , though the latter only occurred before high vowels. Both and could be used unetymologically to mark syllable boundaries; typically used for , as in (genitive singular of 'way') instead of the also attested , while was silent, as in ('Israeli'). The
digraph was sometimes used for the sequence ; both and ('animal'), both pronounced are attested in the corpora. The sound could be represented with either or . In the , a document found west of the Lauwers, the language shows signs of voicing in word-initial fricatives like that found in Middle and Modern Dutch, though this does not persist in Modern West Frisian.
Dialectal variation Old Frisian phonology was not uniform. For example, around the year 1200, the
Proto–West Germanic phoneme became in word-medial and word-final positions in several Old Frisian dialects. This change did not affect Old Weser Frisian or North Frisian and forms like existed beside in different dialects during the same period.
Old Weser Frisian Short vowels in unstressed final syllables in Old Weser Frisian were in
complementary distribution; this distribution is called "vowel balance". When the preceding vowel is short and the introduction of vowel balance would cause the additional short vowel to be in an open syllable, or appear, such as in ('to God') or ('ships'). If the preceding vowel was long or a diphthong, or if the stem vowel was separated by another syllable, the word ended with the vowels or , such as in ('people'). This regular distribution of word-final vowels has allowed linguists to differentiate between long and short vowels in Old Frisian documents where vowel length is not marked. For example, the word (dative singular of 'hoof'), with a long first vowel, could be distinguished from its short vowel counterpart (dative singular of 'court, courtyard'). The consequences of vowel balance are reflected in two of the descendant dialects,
Wangerooge and
Wursten. Old Weser Frisian also raised to before (, 'earth') and raised and to through
i-mutation (, 'king'). However, was lowered to and to in open syllables if the following syllable contains . This last process is known as the Rüstring
a-mutation. Following fronting and the palatalization of and , which typically became , Old Weser Frisian exhibits , such as in ('day') instead of and ('brain') instead of . Proto-Germanic also became .
Old Ems Frisian Old Ems Frisian diphthongized to before a voiced
alveolar consonant including
resonants, as in ('bride', also 'broad'). In unstressed syllables, the suffix inserted between the vowel and the final consonant, such as in ('weapon') instead of . In later forms of the dialect, became lengthened after some consonant clusters; then had a tendency to become rounded to () irrespective of if it had been lengthened by the consonant cluster lengthening. This gave rise to forms such as ('all') instead of , though forms like ('so') – against the non-Ems form – show rounding but not in both circumstances.
Old West Frisian Orthographic conventions used in Old West Frisian help to make the phonological structure much clearer than those of the Old East Frisian dialects. Vowel length is frequently marked, either with the addition of an after the long vowel, as in ('book'), or the duplication of the long vowel, as in ('house') or ('woman'). Orthographic duplication of long was sometimes and sometimes , as in . Similarly, a long may sometimes be represented as , as in ('his'), or , as in ('
wergeld'). In some instances, or may be used as a length modifier as well, as in ('sign') or ('known, public'). Old West Frisian demonstrates rounding of before
nasal consonants; this was later constrained to the northeastern dialect before or , as the southwestern dialect restored it to . When occurred between vowels, it became , as in instead of for the dative singular of 'court'; this also sometimes led to the collapse of the two vowel structure, causing a diphthong to occur, as in ('head'; from earlier inherited from ). This sound change is also found in later forms of the Old East Frisian dialects. Old West Frisian also exhibits several
vowel breaking processes. One is a process called "Jorwert breaking" where long front vowels followed by are converted into rising diphthongs. This means that , , and were converted into , , and , respectively. Sometimes the is deleted if it follows an . Before consonant clusters beginning with a
liquid consonant, is typically raised to . In another process, called "late Old West Frisian breaking", consonant clusters where preceded , , , or , the preceding was lengthened, diphthongized, and stress shifted to the second syllable. This process can be seen in examples such as lengthening to before breaking into ; stress originally fell on the first syllable, then shifted to the final syllable. Before the cluster , diphthongizes to . In the sequence , both elements merge into . The diphthong raised to , pronounced as . The
voiceless dental fricative became word-initially and the
voiced dental fricative, also represented as became word-initially and -medially. Between vowels, – including those previously dental fricatives – are elided, as in ('to cut'; from earlier ). Word-final was devoiced and was raised to before nasal consonants. ==Morphology==