Old English phonology

Old English phonology is necessarily somewhat speculative since Old English is preserved only as a written language. Nevertheless, there is a very large corpus of the language, and the orthography apparently indicates phonological alternations quite faithfully, so it is not difficult to draw certain conclusions about the nature of Old English phonology.

Old English had a distinction between short and long (doubled) consonants, at least between vowels (as seen in "sun" and  "son",  "to put" and  "to steal"), and a distinction between short vowels and long vowels in stressed syllables. It had a larger number of vowel qualities in stressed syllables – and in some dialects  – than in unstressed ones –. It had diphthongs that no longer exist in Modern English, which were, with both short and long versions.

Consonants
The inventory of consonant surface sounds (whether allophones or phonemes) of Old English is as shown below. Allophones are enclosed in parentheses.

Intervocalic voicing
The fricatives had voiced allophones, which occurred between vowels or a vowel and a voiced consonant when the preceding sound was stressed.
 * stæf ('letter') :
 * stafas ('letters') >
 * smiþ ('blacksmith') :
 * smiþas ('blacksmiths') >
 * hūs ('house' noun) :
 * hūsian ('to house') >
 * forþ ('forth') :
 * compare eorðe ('earth') >
 * fæþm ('fathom') >

Proto-Germanic (a fricative allophone of ) developed into the OE stop, but Proto-Germanic  (a fricative allophone of ) developed into the OE fricative  (either its voiced allophone  or its voiceless allophone [f]).
 * PG  > OE fæder
 * PG  > OE stæf
 * PG > OE habban, hæfde,  '(to) have, had'

Dorsal consonants
Old English had a fairly large set of dorsal (postalveolar, palatal, velar) and glottal consonants:. Typically only are analyzed as separate phonemes;  is considered an allophone of,  an allophone of , and  and  allophones of.

Historically, developed from  by palatalization, and some cases of  developed from palatalization of, while others developed from Proto-Germanic. (Although this palatalization occurred as a regular sound change, later vowel changes and borrowings meant that the occurrence of the palatal forms was no longer predictable, that is, the palatals and the velars had become separate phonemes.) Both the velars (including ) and the palatals  (including ) are spelled as,  in Old English manuscripts.

In modern texts, the palatalized versions may be written with a dot above the letter:,. (As just mentioned, it would otherwise not generally be possible to predict whether a palatal or velar is meant, although there are certain common patterns; for example, often has the palatalized sound before the front vowels, , . Note that Old English had palatalized  in certain words that have hard G in Modern English due to Old Norse influence, such as ġiefan "give" and ġeat "gate".)

was pronounced as in most cases, but as the affricate  after  or when geminated (fortition). The voiced velar fricative was pronounced as the stop  after  or when doubled. In late Old English, was devoiced to  at the ends of words. Because of this, and the palatalization referred to above, the phonemes, , and came to alternate in the inflectional paradigms of some words.
 * dæġ ('day')
 * dæġes
 * dagas
 * dagung ('dawn')
 * burg, burh ('castle') >
 * burgum
 * byrġ
 * senġan ('to sing') >  (from )
 * bryċġ ('bridge') >  (from  < )

In late Old English, appeared in initial position as well, and  became an allophone of, occurring only after a vowel.

are allophones of occurring word-initially and after a front vowel respectively.
 * hund ('dog') >
 * cniht ('boy') >

The evidence for the allophone after front vowels is indirect, as it is not indicated in the orthography. Nevertheless, the fact that there was historically a fronting of to  and of  to  after front vowels makes it very likely. Moreover, in late Middle English, sometimes became  (e.g. tough, cough), but only after back vowels, never after front vowels. This is explained if we assume that the allophone sometimes became  but the allophone  never did.

Sonorants
is an allophone of occurring before  and. Words that have final in standard Modern English have the cluster  in Old English.
 * sincan ('sink') >
 * hring ('ring') >

The exact nature of Old English is not known. It may have been an alveolar approximant, as in most Modern English accents, an alveolar flap , or an alveolar trill.

were pronounced as voiceless sonorants following.
 * hwæt ('what')
 * hlāf ('bread') (Modern English loaf)
 * hnutu ('nut')
 * hring ('ring')

However, it is also commonly theorized that the ⟨h⟩ in these sequences was unpronounced, and only stood for the voicelessness of the following sonorant.

Velarization
apparently had velarized allophones and, or similar, when followed by another consonant or when geminated. This is suggested by the vowel shifts of breaking and retraction before, which could be cases of assimilation to a following velar consonant: Due to phonotactic constraints on initial clusters, ⟨wr⟩ and ⟨wl⟩ are thought by some to be digraphs representing these velarized sounds, in which case the distinction was phonemic:
 * *lirnian > liornian > leornian ('learn')
 * *erþǣ > eorþǣ > eorþe ('earth')
 * *fællan > feallan ('to fall')
 * wrīdan: "to grow"
 * rīdan: "to ride"
 * wlītan: "to look"
 * lītan: "to bend"

However, this theory is inconsistent with orthoepic and orthographic evidence from the Early Modern English era, as well as borrowings into and from Welsh, which has and  as genuine initial clusters.

Vowels
Old English had a moderately large vowel system. In stressed syllables, both monophthongs and diphthongs had short and long versions, which were clearly distinguished in pronunciation. In unstressed syllables, vowels were reduced or elided, though not as much as in Modern English.

Monophthongs
Old English had seven or eight vowel qualities, depending on dialect, and each could appear as either a long or short monophthong. An example of a pair of words distinguished by vowel length is god ('god') and gōd  ('good').

The front mid rounded vowel occurs in the Anglian dialects, for instance, but merged into  in the West Saxon dialect.

The long–short vowel pair developed into the Middle English vowels, with two different vowel qualities distinguished by height, so they may have had different qualities in Old English as well.

The short open back vowel before nasals was probably rounded to. This is suggested by the fact that the word for "person", for example, is spelled as mann or monn.

In unstressed syllables, only three vowels,, were distinguished. Here were reduced to ;  were reduced to, and  remained. Unstressed were sometimes pronounced/ spelled as  in closed syllables, as in hāliġ and heofon.

Diphthongs
All dialects of Old English had diphthongs. Like monophthongs, diphthongs appear to have had short and long versions. In modern texts, long diphthongs are marked with a macron on the first letter. The short versions behave like short monophthongs, and the long versions like long monophthongs. Most Old English diphthongs consist of a front vowel followed by a back offglide; according to some analyses they were in fact front vowels followed by a velarized consonant. The diphthongs tend to be height-harmonic, meaning that both parts of the diphthong had the same vowel height (high, mid or low).

The Anglian dialects had the following diphthongs:

The high diphthongs io and īo were not present in West Saxon, having merged into eo and ēo. Early West Saxon, however, had an additional pair of long and short diphthongs written ie (distinguished as ie and īe in modern editions), which developed from i-mutation or umlaut of eo or ea, ēo or ēa. Scholars do not agree on how they were pronounced; they may have been or. They were apparently monophthongized by Alfred the Great's time, to a vowel whose pronunciation is still uncertain, but is known as "unstable i". This later went on to merge with, according to spellings such as gelyfan, for earlier geliefan and gelifan ('to believe'). (According to another interpretation, however, the "unstable i" may simply have been, and the later can be explained by the fact that Late West Saxon was not a direct descendant of Early West Saxon. See Old English dialects.) This produced additional instances of  alongside those that developed from i-mutation and from sporadic rounding of  in certain circumstances (e.g. myċel 'much' from earlier miċel, with rounding perhaps triggered by the rounded ). All instances of were normally unrounded next to,  and , hence ġifan from earlier ġiefan 'to give'.

Origin of diphthongs
Old English diphthongs have several origins, either from Proto-Germanic or from Old English vowel shifts. Long diphthongs developed partly from the Proto-Germanic diphthongs and partly from the Old English vowel shifts, while the short diphthongs developed only from Old English vowel shifts. These are examples of diphthongs inherited from Proto-Germanic:
 * PG > Anglian bīom, West Saxon bēo '[I] am'
 * PG > OE dēor 'animal' > Modern English deer
 * PG > OE dēaþ 'death'

There are three vowel shifts that resulted in diphthongs: breaking, palatal diphthongization, and back mutation. Through breaking, Anglo-Frisian short developed into the short diphthongs io, eo, ea before  or a consonant cluster beginning with, and Anglo-Frisian long  developed into the diphthongs īo and ēa before. Palatal diphthongization changed e, æ and a, ǣ, u and o, ē to the diphthongs ie, ea, ēo, ēa respectively after the palatalized consonants ġ, sċ, and ċ (though this may have only been a spelling change). Back mutation changed i, e, and sometimes a to io, eo, and ea before a back vowel in the next syllable.
 * PG > Anglo-Frisian  > Anglian liornian, West Saxon leornian 'learn' (breaking)
 * PG > AF  > Old English nēah 'near' (breaking)
 * PG > AF  > ġiefan 'give' (palatal diphthongization)
 * PG > AF  > OE seofon 'seven' (back mutation)

Scholars disagree on whether short diphthongs are phonologically possible, and some say that Old English short diphthongs must actually have been centralized vowels. Hogg argues against this, saying that a length contrast in diphthongs exists in modern languages, such as Scots, in which the short diphthong in tide contrasts with the long diphthong in tied.

Peter Schrijver has theorized that Old English breaking developed from language contact with Celtic. He says that two Celtic languages were spoken in Britain, Highland British Celtic, which was phonologically influenced by British Latin and developed into Welsh, Cornish, and Breton, and Lowland British Celtic, which was brought to Ireland at the time of the Roman conquest of Britain and became Old Irish. Lowland British Celtic had velarization like Old and Modern Irish, which gives preceding vowels a back offglide, and this feature was loaned by language contact into Old English, resulting in backing diphthongs.

Phonotactics
Phonotactics is the study of the sequences of phonemes that occur in languages and the sound structures that they form. In this study it is usual to represent consonants in general with the letter C and vowels with the letter V, so that a syllable such as 'be' is described as having CV structure. The IPA symbol used to show a division between syllables is the dot. Old English stressed syllables were structured as (C)3V(C)3; that is, up to three consonants in both the onset and coda with one vowel as the nucleus.

Onset
Onset clusters typically consist of a fricative and a stop, although  is allowed as a third element before voiceless stops. The other onset consonants (and  if these are accepted as existing) always occur alone. Alternatively, the voiceless sonorants can be analyzed as clusters of  and a voiced sonorant:. Conversely, the clusters of and a voiceless stop-  can be argued to be phonemic, although no analyses do so.

Nucleus
The syllable nucleus was always a vowel.

Sound changes
Like Frisian, Old English underwent palatalization of the velar consonants and fronting of the open vowel  to  in certain cases. It also underwent vowel shifts that were not shared with Old Frisian: smoothing, diphthong height harmonization, and breaking. Diphthong height harmonization and breaking resulted in the unique Old English diphthongs io, ie, eo, ea.

Palatalization yielded some Modern English word-pairs in which one word has a velar and the other has a palatal or postalveolar. Some of these were inherited from Old English (drink and drench, day and dawn), while others have an unpalatalized form loaned from Old Norse (skirt and shirt).

Dialects
Old English had four major dialect groups: Kentish, West Saxon, Mercian, and Northumbrian. Kentish and West Saxon were the dialects spoken south of a line approximately following the course of the River Thames: Kentish in the easternmost portion of that area and West Saxon everywhere else. Mercian was spoken in the middle part of the country, separated from the southern dialects by the Thames and from Northumbrian by the River Humber. Mercian and Northumbrian are often grouped together as "Anglian".

The biggest differences occurred between West Saxon and the other groups. The differences occurred mostly in the front vowels, and particularly the diphthongs. (However, Northumbrian was distinguished from the rest by much less palatalization. Forms in Modern English with hard  and  where a palatalized sound would be expected from Old English are due either to Northumbrian influence or to direct borrowing from Scandinavian.  Note that, in fact, the lack of palatalization in Northumbrian was probably due to heavy Scandinavian influence.)

The early history of Kentish was similar to Anglian, but sometime around the ninth century all of the front vowels æ, e, y (long and short) merged into e (long and short). The further discussion concerns the differences between Anglian and West Saxon, with the understanding that Kentish, other than where noted, can be derived from Anglian by front-vowel merger. The primary differences were:
 * Original (post Anglo-Frisian brightening) ǣ was raised to ē in Anglian but remained in West Saxon. This occurred before other changes such as breaking, and did not affect ǣ caused by i-umlaut of ā.  Hence, e.g., dǣlan ('to divide') <  appears the same in both dialects, but West Saxon slǣpan ('to sleep') appears as slēpan in Anglian. (Note the corresponding vowel difference in the spelling of "deal" < dǣlan vs. "sleep" < Anglian slēpan.)
 * The West Saxon vowels ie/īe, caused by i-umlaut of long and short ea, eo, io did not appear in Anglian. Instead, i-umlaut of ea and rare eo is spelled e, and i-umlaut of io remains as io.
 * Breaking of short to ea did not happen in Anglian before +consonant; instead, the vowel was retracted to .  When mutated by i-umlaut, it appears again as æ (vs. West Saxon ie).  Hence, Anglian cald ('cold') vs. West Saxon ċeald.
 * Merger of eo and io (long and short) occurred early in West Saxon, but much later in Anglian.
 * Many instances of diphthongs in Anglian, including the majority of cases caused by breaking, were turned back into monophthongs again by the process of "Anglian smoothing", which occurred before c, h, g, alone or preceded by r or l. This accounts for some of the most noticeable differences between standard (i.e. West Saxon) Old English and Modern English spelling.  E.g. ēage ('eye') became ēge in Anglian; nēah ('near') became Anglian nēh, later raised to nīh in the transition to Middle English by raising of ē before h (hence nigh in Modern English); nēahst ('nearest') become Anglian nēhst, shortened to nehst in late Old English by vowel-shortening before three consonants (hence next in Modern English).

Modern English derives mostly from the Anglian dialect rather than the standard West Saxon dialect of Old English. However, since London sits on the Thames near the boundary of the Anglian, West Saxon, and Kentish dialects, some West Saxon and Kentish forms have entered Modern English. For example, bury has its spelling derived from West Saxon and its pronunciation from Kentish (see below).

Examples
The prologue to Beowulf:

The Lord's Prayer: