ym Mangor, yŋ Ŋwynedd. With our present alphabet we have to write the last yng Ngwynedd; so yng Nghadelling. It is objected to this that it is clumsy; but that is the fault of the alphabet. It is the only way of expressing the sound fully and correctly, and is the exact equivalent in modern characters of the Ml. W. yggwyned w.m. 108, yg gadellig w. 90, § 24 i.
(6) There are, however, a number of adverbial and prepositional expressions, in which yn, followed by the nasal mutation, is wholly unaccented. In this case the nasal is single, as after fy; and the preposition is naturally joined to its noun, exactly like the in in the Eng. indeed. These expressions are ynghyd, ynghylch, ynglŷn, yngholl, ynghudd, ymhell, ymhlith, ymysg, ymron, ymlaen, ymhen, yngham, ymhellach, ynghynt, etc. No principle of accentuation is violated in this spelling, as asserted by Silvan Evans, Llythyraeth 50, who recommends yng nghyd etc. See above § 47 ii.
The Spirant Mutation.
§ 108. i. Brit. or Lat. pp, tt, kk gave W. ff, th, ch respectively. Thus W. cyff ‘stem’ < Lat. cippus; Brython < Brit. Brittones; pechod < Lat. peccātum; hwch: Ir. socc, etc., § 93 iii (2). It occurs when an initial tenuis follows an explosive in word-composition, as in achas § 93 ii (2), athech § 93 iii (1), athrist § 99 v (4). This is called the “spirant mutation” of the tenuis.
ii. In Brit. s + tenuis had already become a double spirant § 96 i; and original oxytones ending in ‑s caused the spirant mutation of a following initial tenuis § 103 i (3), as tri chant ‘300’. In this case th- and ph- were chosen as the mutations of t- and p‑, as their relation to the radicals is clearer than that of the alternative forms s, χu̯.
iii. The spirant mutation after chwe ‘six’ is irregular. From Kelt. *su̯eks kantom we should expect *chwe cant, since ksk gives sk, and final ‑s would drop. But the independent form of *su̯eks was already *χu̯eχ in Brit.; and we may assume that this was generalized, so that the ch- in chwe chant comes from ‑χ k‑.
iv. (1) Brit. or Lat. kt > *χ̑t > *χ̑þ > i̯þ; the i̯ forms i-diphthongs § 29 i, cf. § 104 ii (1); thus akt > aeth; okt > oeth; ukt > w͡yth; ekt > eith, Mn. aith; ikt > īth. Thus W. caeth < Brit. *kaktos § 86 ii (1); doeth < Lat. doctus; ffrwyth < Lat. fructus; saith Brit. *sehtan < Ar. *septm̥; perffaith < Lat. perfectus; brith < Brit. *briktos < *bhr̥ktos § 101 iii (2); eithin
