huawdɏl r.p. 1301.) It is probable that the misspelling boreu for bore § 31 ii 2 sprang from boreuach the debased form of boryach.
(4) yw follows the rule, as bɥw, bỿwɥd, bỿwi̯og; clɥw, clỿwed; llɥw, llỿwɥdd, llỿwi̯o, etc., except in late formations, especially from forms in which ɥw became iw § 77 v, as in amrɥwi̯o (sounded amriwi̯o), distrɥwi̯af (distriwi̯af), etc. J.D.R. writes amrywio (y ≡ ɥ) [xvi], distriwiaw [xix]. So niwli̯og, niwloedd § 37 ii.
(5) The rising diphthong w̯y follows the rule: gw̯ɥrdd, gw̯ỿrddi̯on, etc.; but w̯ỿ generally becomes w § 66 ii. Such a pronunciation as gw̯ɥntoedd is recent; but gw̯ɥwo ‘to wither’ may be old, as the ɥ may have resisted mutation between two w̯’s.
(6) The rule does not apply to the falling diphthong w͡y, in which the y is consonantal. In this y must necessarily be ɥ always, as mŵyn, mw͡ynach, mw͡yni̯on; and the ɥ remains when the w͡y is mispronounced as w̯ɥ § 38 iii, as Gw̯ɥ́nedd for Gw͡ynedd.
iii. (1) In the words sylw, gw̯yry, the final w and y were non-syllabic § 42, § 110 ii; hence the y is ɥ; thus sɥlw (but sỿlw̯i), gw̯ɥrỿ.
(2) With the exceptions mentioned in ii, the sound which is now common to y and u, if it occurs in the penult, is to be written u. Thus we write munud, munudau, papur, papurau. Following this rule the translators of the Bible were misled by the late disyllabic pronunciation of sylw to write it sulw; in late editions this error is corrected.
(3) In a few cases u in the ultima has come to be mistaken for y and mutated to ỿ in the penult; as in ysgrythyrau in the Bible (but ysgrythurau correctly in the 1727 edn.) pl. of ysgrythur (< Lat. scriptūra) regarded as ysgrythyr on the analogy of llythyr ‘letter’. So testynau for testunau, Early Mn. W. testunion, pl. of testun (<Lat. testimōnium) treated as testyn; corynau ‘crowns’, corynfoel b.cw. 33 ‘bald-headed’, from corun r.b.b. 171 (< Lat. corōna) treated as coryn.
Vowel Affection.
§ 83. The following tables show the affected and unaffected forms of vowels as they alternate in Mn. W.
i. Ultimate a-affection, § 68.
| No. | Unaffected. | Affected. | Examples. |
| 1 | ɥ | e | gwɥ̆n, f. gwĕn; crȳf, f. crēf |
| 2 | w | o | trw̆m, f. trŏm; tlw̄s, f. tlōs |
