The order of the changes was the following: yn ‘in’ + Bangor first became ym Bangor, and then ym Mangor. The recent spelling yn Mangor is therefore not only a misrepresentation of the present sound, but a falsification of its history.
(2) There is a sporadic assimilation of n to i in the groups ĭn or ein, the n becoming ŋ̑; thus pringhaf r.p. 1278, spv. of prĭn ‘scarce’ ib. 1280 (< *qu̯rīt-sno‑s: prid ‘precious’, √qu̯reiā- ‘buy’); meithring (‑iŋ̑) D.G. 69 for meithrin ‘to nourish’; Einion is often written Eingion or Eingnion ≡ eiŋ̑on, which has become eŋŋan in Gwynedd, e.g. Llan-engan near Pwllheli.
ii. (1) Brit. mb, nd, ŋg became respectively mm, nn, ŋŋ: they remain so in W., mm being generally written m; nn finally written -n (but -nn in monosyllables in Ml. W.); ŋŋ written ng (and Ml. W. gg or g); see § 51 iv, § 54 i (2). Thus W. cwm ‘valley’ < Brit. *kumbo-, √qeub/p- ‘curve’: Lat. cūpa, ‑cumbo, Gk. κύμβος, etc.;—W. cam ‘bent, crooked’ < Brit. *kambo-: Gaul. Cambo-dūnum, Gallo-Lat. cambiāre: Lat. campus (orig. ‘vale’), Gk. καμπή, κάμπτω, √qamb/p- ‘curve’;—W. twnn ‘bruised, broken’ f. tonn < Brit. *tund-os, -ā: Lat. tundo, Skr. tundate ‘strikes’, √(s)teu‑d‑;—W. tonn ‘wave’ < Brit. *tundā < *tum-dā: Lat. tumeo, W. tyfu, √teu̯āˣ- ‘swell’;—W. cann ‘white’, cannu ‘to whiten’, llóer-gan ‘moon-lit’ < *qand‑: Lat. candeo, Gk. κάνδαρος < *qand‑, beside W. cynneu ‘to kindle’, cynne ‘a burning’, cynnud ‘firewood’, Ir. condud < *qond‑: Skr. cand‑, s̑cand‑ ‘shine’ < *(s)qend‑: √sqand‑/sqend‑;—W. llong ‘ship’ < Lat. longa;—W. angel < Lat. angelus.—So before a sonant, as Cymro pl. Cymry < Brit. *kom-brog-os, ‑ī;—W. amrwd ‘raw’: brwd § 63 vii (4);—Cyngreawdr § 104 iii (2);—except where the nasal has become a media § 99 vi (1).—The double nasal was simplified after an unaccented syllable § 27 ii, and before a sonant § 54 i (3).
