- b. Before the labials, n becomes m in modern Gaelic. Before t, c, the n disappears with lengthening of the previous vowel, as in ceud, first, breug, cóig. Before d and g, it is preserved, as in cumhang, fulaing, muing, seang, but it assimilates d—fionn (*vindo‑s), bonn, inn‑, binn. For ‑ngm, see under ṇ and g.
- c. Before s, n disappears as before t and c. Compare mìos, feusag, grìos, sìos.
(5) Post-consonantal n disappears after l, leaving ll (see under l), but is preserved after r, as in càrn, eòrna, tighearna, etc.
- a. After s, that is, ‑sn becomes ‑nn; as in dronn for *dros-no‑, donn, uinnsean, cannach, bruinne, etc.
- b. The mutes, t, d, c, g, p, disappear with compensatory lengthening of the previous vowel: ‑tn‑, as in eun, buan, ùin; ‑dn‑, as in bruan, smuain; ‑cn- is doubtful—cf. tòn, also sgeun, breun, leòn; ‑gn, as in feun, bròn, uan, sròn; ‑pn, as in suain, cluain, cuan; ‑pn? tepno = tĕn; apnio = ăne (Lit. aps); lipn = lĕn, follow; but supn = suan; copn = cuan (Stokes); cn, gn, and tn initial become r in pronouncing; but the vowel is nasal—gnàth is gràth with nasal à; bn becomes mn, as in mnaoi, pronounced mraoi; even snàth becomes dialectally sràth, especially in oblique cases.
- c. After b, that is, bn changes into mh‑n, as in domhan (*dubno‑), sleamhuinn.
The G. combination ‑nn arises therefore from (1) n before n, (2) n before d, and (3) from ‑sn; or (4) it is a doubling of n in an unaccented syllable at the end of a word (tighinn, etc.), or, rarely, of a one-syllable word like cinn, cluinn, linn. In Islay, ‑in becomes ‑inn; duinne is for duine; minne gen. of min, etc. In general, gloinne is comp. of glan.
Initial m appears in mìos, muir, mil, maide, etc. Before the liquids r and l, the m becomes b, as in braich, brath, brugh, blàth, bleith, bleoghainn. Intervocalic m is always aspirated—geimheal, amhuil, like, cruimh, amh, damh, cnàimh, làmh, caomh. In combinations with other consonants, various results occur:—
(1) Pre-consonantal m.
- a. Before liquids, m is preserved in an aspirated form (geamh-radh, etc.), but there are no certain ancient cases. Of course, m before m results in preserved m (cf. amadan, comas, comain).
