This is a presentation of the phonological history of the Scots language. Scots has its origins in Old English (OE) via early Northern Middle English; though loanwords from Old Norse and Romance sources are common, especially from ecclesiastical and legal Latin, Anglo-Norman and Middle French borrowings. Trade and immigration led to some borrowings from Middle Low German and Middle Dutch. Some vocabulary has been borrowed from Scotland's other language, Scottish Gaelic.

Consonants

Instance of between and a following or /r/ were lost or did not develop: Certain clusters were reduced: While OE became in Modern English, Scots has retained the original pronunciation (e.g. OE sċylfe, 'shelf', became skelf). Old English became when adjacent to a front vowel (e.g. shinners from OE sinder, 'cinder'). OE was often dropped in certain contexts: In contexts where OE and palatalized to and, respectively, in Modern English (that is, after a front vowel), Scots has retained the original velar pronunciation: Word final OE (written ⟨ð⟩ or ⟨þ⟩) was deleted in a few words (e.g. OE mūþ, 'mouth', became mou in Scots). OE was lost in English, but remained in Scots, spelled ⟨ch⟩: However, some words such as tho (though) and throu ('through') have dropped the. Old English became for a number of speakers, though is widespread (e.g. OE hwæt, 'what', became whit). Metathesis occurred in some words (e.g. OE græs, 'grass', became girse). OE became vocalised after resulting in the diphthong in Modern Scots (e.g. boga, 'bow', became bowe). Similarly, in the Early Scots period, was vocalized after:

Vowels

The following table shows the modern realisation of the various Scots vowels along with their pronunciation in Early Scots, the Early Middle English vowels they can largely be derived from, and the main Old English sources of these vowels. See also Middle English phonology for a more in-depth overview of the Old English sources of the Early Middle English vowels below. External sources are: For the principal Old English, Norse and Romance sources of the Early Scots vowels see Aitken, A.J, (Ed. Macafee C.) (2002) pp. 89–95; for an overview of the historical developments see Vowel systems of Scots: a rough historical outline in A History of Scots to 1700, p. lvii.

Vowel 1

Old English and Old Norse ī and ȳ, Old English i+ld and y+nd, as well as Old French i became in Early Scots then in Middle Scots and subsequently conditioned by the Scottish Vowel Length Rule to when short and or when long in Modern Scots, for example: wyce (wise), wyte (blame), bide (remain), kye (cows), hive and fire from wīs, wīte, bīdan, cȳ, hȳf and fȳr. Similarly with Norse grice (pig), sile (strain), tyke (curr), lythe (shelter) and tyne (lose), and Romance advice, fine, cry, sybae (onion) but where Romance words entered Scots after this sound shift the original (Vowel 2) remained in Scots, for example bapteese (baptise), ceety (city), ceevil (civil), eetem (item), leeberal (liberal), leecence (license), meenister (minister), obleege (oblige), peety (pity), poleetical (political), poseetion, releegion (religion) and speerit (spirit). Similarly with Old French ai and ei, for example Modern Scots chyce (choice), eynment (ointment), eyster (oyster), evyte (avoid), jyne (join), ile (oil), pynt (point), syle (soil), spyle (spoil) and vyce (voice)

Vowel 2

Old English ē became in Early Scots then in Middle Scots and in Modern Scots, for example: bee, breest breast, cheese, creep, deed, freend (friend), hear, heich (high), knee, seek (sick), sheep, sleep, teeth and wheen a few from bēo, brēost, ċēse, crēap, dēd, frēond, hēran, hēah, cnēo, sēoc, sċēp, slēp, tēþ and hwēne. Also grieve (overseer) from grœfa.

Vowel 3

Old English ea and ēa became in Early Scots, merging with vowel 2 or vowel 4 in Middle Scots depending on dialect or lexeme, except for a few Northern Scots dialects where it became, for example Modern Scots: beard, breid (bread), deid (dead), deif (deaf), heid (head), meat (food), steid (stead) and tread from beard, brēad, dēad, dēaf, hēafod, mete, stede and tredan. Similarly with Romance words like beast, cheat, conceit, creitur (creature), deceit, ease, please, ream (cream), reison and seison.

Vowel 4

Old English ā became in Early Scots then in Middle Scots and in Modern Scots, for example: aik (oak), ait (oat), braid (broad), gae (go), hale (whole), hame (home), lade (load), mair (more), raip (rope), saip (soap), sair (sore) and nae (no) from āc, āte, brād, gā, hāl, hām, lād, māra, rāp, sāp and nā. Before, now in Modern central, southern and Ulster varieties and in northern varieties, for example: ane (one), ance (once), bane (bone), gane (gone), nane (none) and stane (stone) from ān, ānes, bān, gān, nān and stān. Similarly with Norse, for example frae (from), kail (cole) and spae (foretell) from frá, kál and spá. The vowel occurs in other words of Norse origin, for example graith (harness), hain (spare) and lair (mud) from greiða, hagna and leir. Before + consonant, depending on dialect, now or in Modern Scots, for example: airm (arm), airae (arrow), bairn (child), dairn (darn), hairm (harm), hairst (harvest), wairm (warm) and shairp (sharp) from earm, arwe, derne, hearm, hærfest, wearm and sċearp. Similarly with aiple (apple), aix (axe), efter (after), peth (path), and wraith (wrath) from æpel, æx, æfter, pæþ and wræþþu. Similarly with Romance caird (card), cairy (carry), gairden (garden), regaird (regard), mairy (marry), mairtyr (martyr) and pairt (part).

Vowel 5

In open position o became in Early Scots then eventually in Modern Scots, for example: coal, foal, hole and thole endure.

Vowel 6

Old English ū became in Early Scots then in Middle Scots, remaining so but Stem final it became in Southern Scots, for example Modern Scots: brou (brow), broun (brown), cou (cow), dou (dove), doun (down), house (house), hou (how), mou (mouth), mouse (mouse), nou (now), sour (sour) and thoum (thumb) from brū, brūn, cū, dūfe, dūn, hūs, hū, mūþ, mūs, nū, sūr and þūma. Similarly with Norse boun (ready), couer (cower), droup (droop) and stroup (spout), and Romance allou (allow), bouat (lantern), count (count), dout (doubt), pouder (powder) and round (round).

Vowel 6a

Older Scots became vocalised to by the Middle Scots period, for example Modern Scots: fou (full), pou (pull) and oo (wool) from full, pullian and wull. Similarly Romance coum (culm) and poupit (pulpit).

Vowel 7

Old English ō, ēo became in Early Scots becoming in Modern peripheral dialects. In Fife and parts of Perthshire Middle Scots merged with vowel 4. In Modern central varieties it has merged with vowel 15 in short environments conditioned by the Scottish Vowel Length Rule, for example: bluid (blood), duin (done), muin (moon) and spuin (spoon) from dōn, blōd, mōna, and spōn. Similarly with Romance words like bruit (brute), fruit, schuil (school), tuin (tune), uiss (use n.). In central varieties Middle Scots merged with vowel 4 in long environments conditioned by the Scottish Vowel Length Rule, for example Modern Scots: buird (board), fuird (ford), fluir (floor) and muir (moor) from bōrd, fōrd, flōr and mōr along with dae (do), shae (shoe) and tae (to) from dō, scō and tō. Similarly with Norse words like Fuirsday (Thursday), luif (palm) and ruise (praise), and Romance words like puir (poor), shuir (sure), uise (use v.). In northern varieties Middle Scots merged with vowel 2, in Mid Northern varieties after and it became , for example Modern Scots: guid (good), cuil (cool), from gōd, cōl and Dutch cuit (ankle), and Romance schuil (school). Note: But not Modern Scots fit (foot), wid (wood), wad (would), oo (wool), coud (could) and shoud/su(l)d (should). A following or resulted in Modern Scots, , and/or depending on dialect, for example: beuch (bough), beuk (book), ceuk (cook), eneuch (enough), heuch (cliff), heuk (hook), leuch (laughed), leuk (look), pleuch (plough), sheuch (ditch), teuch (tough) and teuk (took) from bōh, bōc, cōc, ġenóh, hōh, hōc, hlōh, tōc, plōh, sōh, tōh and tōc.

Vowel 8

Old English a or æ in open position became in Early Scots then in Middle Scots and subsequently, or in Modern Scots, though may also occur, especially in Ulster, for example: faither (father), gaither (gather), haimer (hammer), day, brain, fair, nail and tail from fæþer, gaderian, hamer, dæġ, bræġen, fæġer, næġel and tæġel. Similarly with Norse cake, gate (street), sale and scaith (damage).

Vowel 8a

Older Scots stem final became in Middle Scots merging with vowel 1 in Modern Scots.

Vowel 9

Older Scots became in Modern Scots.

Vowel 10

Early Scots merged with vowel 1 in Modern Scots.

Vowel 11

Early Scots in stem final positions, became then in Middle Scots merging with vowel 2 in Modern Scots.

Vowel 12

Old English ag-, aw- and āw became in Early Scots then in Middle Scots and subsequently, depending on dialect, or in Modern Scots, for example: draw, gnaw, and law from dragan, gnagan, haga and lagu, and Norse maw (seagull) and claw from maga and clawa. blaw (blow), craw (crow), maw (mowe), sawe (sow), saul (soul) and snaw (snow) from blāwan, crāwe, māwan, sāwan, sāwol and snāwan. Similarly with Old English āg and Norse lágr which became awn (to own) and law (low). Before and + consonant, Middle Scots also became or in Modern Scots, for example: caunle (candle), draucht (draught), haund (hand), lauch (laugh), saund (sand) and slauchter (slaughter) from candel, draht, hand, hlæhhan, sand and slæ. Similarly with Norse baund (band), Dutch fraucht (freight), and Romance chancy, glanders, graund, and stank (a drain).

Vowel 12a

Older Scots became vocalised to by the Middle Scots period and subsequently, depending on dialect, or in Modern Scots, for example: aw (all), caw (call), fauch (fallow), faw (fall), gaw (gall), haud (hold), haw (hall), maut (malt), sauch (sallow), saut (salt), smaw (small), staw (stall) and waw (wall) from eal, ceallian, fealh, fallan, gealla, healdan, hall, mealt, salh, sealt, smæl, steall and wall. Similarly with Norse hause (neck) and Romance aum (alum), baw (ball) and scaud (scald).

Vowel 13

Old English ów became in Older Scots then in Modern Scots, for example: flowe (flow), glowe (glow), growe (grow) and stowe (stow) from flōwan, glōwan, grōwan and stówiġan.

Vowel 13a

Early Scots became vocalised to by the Middle Scots period and subsequently diphthongised to in Modern Scots. In some dialects this is vocalising to especially before, for example Modern Scots: bowster (bolster), bowt (bolt), cowt (colt), gowd (gold), howe (hollow), knowe (knoll), powe (poll) and towe (toll) from bolster, bolt, colt, gold, holh, cnol, polle and toll. Similarly with Romance rowe (roll) and sowder (solder), also Dutch gowf (golf).

Vowel 14

Older Scots (a) and Older Scots (b(i)) became in Middle Scots then or in Modern Scots.

Vowel 14b(ii)

Older Scots became in Middle Scots then in Modern Scots.

Vowel 15

Old English i and y became in Early Scots, remaining so, but approach in some Modern dialects especially after and, for example Modern Scots: hill, filthy, will, win, wind, whip, whisper and whisky.

Vowel 16

Before alveolars Old English æ became in Early Scots, remaining so, for example Modern Scots: bress (brass), clesp (clasp), ess (ash), fest (fast), gled (glad), gless (glass), gress (grass) and hesp (hasp) from bræs, claspe, æsċe, fæst, glæd, glæs, gæs and hæpse.

Vowel 17

Old English a or æ in close position became in Older Scots, remaining so, although or occasionally occur, for example Modern Scots: back, bath, blad (leaf/blade), cat, clap, hack, mak (make), ram, rax (stretch), tak (take), wall (well for water), wash, watter (water) and waps (wasp) from bæc, bæþ, blæd, catt, clappian, haccian, macian, ram, raxan, tacan, wælla, wæsċan, wæter, and wæps. Similarly with Norse bag, flag (flagstone) and snag and Dutch pad (path). Also before and, for example Modern Scots: can, lang (long), man, pan, sang (song), sank, strang (strong), than (then) and wran (wren) from cann, lang, mæn, panne, sang, sanc, strang, þanne and wrænna. Similarly with Norse bann (curse), stang (sting), thrang (busy) and wrang (wrong). Similarly with Old English o before, , and , for example Modern Scots: craft (croft), crap (crop), drap (drop), laft (loft), pat (pot), saft (soft) and tap (top) from croft, cropp, dropa, loft, pott, softe and top. Similarly with a w before e, for example Modern Scots: wab (web), wast (west), wadge (wedge), twal (twelve) and dwall (dwell) from web, west, weċġ, twelf and dwellan.

Vowel 18

Old English o in close position became in Older Scots then in Modern Scots but in some dialects became, for example: box, lock and rock.

Vowel 19

Old English u became in Early Scots then in Modern Scots, for example but and cut, but in some words it merged with vowel 15, for example Modern Scots: din (dun), hinnie (honey), simmer (summer), son and nit (nut) from dunn, huniġ, sumor, sunne and hnut. Similarly in some Romance words, for example Modern Scots: kimmer (commère), kiver (cover), ingan (onion), stibble (stubble) and tribble (trouble).

Word endings

Various Old English word endings became any of, , , , , or depending on dialect, for example Modern Scots: borrae (borrow), follae (follow), marrae (marrow), meidae (meadow), pillae (pillow), sheddae (shadow), swallae (swallow), weedae (widow) and yallae (yellow) from borgian, folgian, mearh, maedwe, pyle, sċeadu, swelgan/swealwe, widwe and ġeolo. Similarly with Norse windae (window).