13 Nasal Mutation

13.1 The nasal mutation is found almost always after the words fy -- 'my', and yn -- 'in', 'into'. Another possibility we meet is after the word seith -- 'seven'. These words all originally had a nasal letter at the end: *fyn, yn, *septm (cf. Latin septem).

	C > NGH	cyffes > nghyffes, corn > nghorn
	T > NH	tarian > nharian
	P > MH	penn > mhenn, perfedd > mherfedd
	G > NG	gwrda > ngwrda
	D > N	dillad > nillad, deu > neu
	B > M	brenin > mrenin, blwyddyn > mlwyddyn

(The unvoiced stops become aspirated nasals. The voiced stops become unaspirated nasals.)

13.2 The word yn is "assimilated" to the mutated noun. (The nasalisation "spreads back" to yn.)

ym mherfedd y rhyd in the middle of the ford
yng nghorn hela in a hunting horn

13.3 Verbal nouns are not mutated after yn.

13.4

"Pa ffurf y caf i dy gerennydd?"
"Llyma fal y ceffy fy ngherennydd."
Cwsg hi yn nillad gwely.
"I Dduw a ddygaf fy nghyffes."
"Fy ngwyrda cywir," heb yr Hafgan.
Gosod a orug ym mherfedd bogel y darian.
Hyllt yn neu hanner.
"Rhoddaf fy mhryd inneu."
. . . hyd ym mhenn y flwyddyn o'r dydd afory.
Ac ef a gychwyn y nos honno o Arberth, ac a ddaw hyd ym Mhenn Llwyn Diarwya.
Ac ar hynny o giniaw y buant seith mlynedd.

Notes:

Mhenn, capitalised as if it were a place name, like Penn-y-bont -- 'Bridgend', but it needn't be.
(See sentence 7 of 10.7.)

	ym mherfedd y rhyd	in the middle of the ford
	yng nghorn hela	in a hunting horn