81. The only single consonants that occur in Latin at the end of a word are b, c, d, l, m, n, r, s, t. The only groups (in words preserved) are ks, nt, st.
Single Final Consonants.
82. D, n, r, t at the end of proclitics (ad, in, per, et) are really medial consonants and must be distinguished from final n, r, t in independent words (nōmen, frater, amat); final d occurs only in proclitics. The consonants will be treated in alphabetical order:—
B appears as b in Iacǫb, p in Iǫp, both learned.
C apparently fell after all vowels in some dialects; in others it fell only after back vowels, and became i after a and front vowels: eccu’hŏc (§ [55], W) ＞ acǫ (§ [43], 2), ecce hŏc ＞ aissǫ çǫ sǫ, hŏc ＞ ǫ meaning ‘it’ (while ǫc, ‘yes’ probably comes from ✱hocque: cf. A. Thomas in Rom., XXXVII, 322); fac ＞ fai, illác (§ [16], 4) ＞ lai la, ecce hac ＞ sai sa; dīc ＞ di, ecce hīc ＞ eici, sīc ＞ si. Düi ＜ dūc may perhaps be explained as due to the analogy of düire and of fai. Cf. § [63], (6).
D in apud fell early: see § [65], P, 2. In the proclitics ad, quĭd, the d disappeared before a consonant, and before a vowel became in most dialects ð ＞ z (cf. § [65], D): a, quẹ; að az, quẹð quẹz.
L fell in in sĭmul ＞ essẹm. It remained in the learned Abęl, tribunal. It is believed by some that sivals, ‘at least’, comes from sī vel.
M fell in Vulgar Latin at the end of a word of more than one syllable (§ [55], M): crēdam crēda ＞ crẹza, dōnum dōnu ＞ dọn, fŏrtem fŏrte ＞ fǫrt; Adam is learned. At the end of an independent monosyllable, it fell in some dialects and in others became n (cf. § [65], N): jam ＞ ia, rĕm ＞ rẹ rẹn (Marcabru uses rẹy for the rhyme), sŭm (verb) ＞ sọ sọn. At the end of proclitics, m was probably kept at first before vowels and labials, while it became n before dentals, ŋ before gutturals, and disappeared before spirants; but the n forms (helped by the analogy of en, non) and those without a final consonant replaced m before vowels and partly before labials, and probably took the place of ŋ before gutturals; we find, then, sometimes m before labials, but either no consonant or n before all other sounds: quĕm ＞ que, sŭm (verb) ＞ sọ sọn, sŭm (= sŭum) ＞ sọ sọn sọm, ✱tŭm (= tŭum) ＞ tọ tọn tọm.
N fell in Vulgar Latin at the end of a word of more than one syllable (§ [55], M): nōmen nōme ＞ nọm. At the end of proclitics we generally find n before a vowel, a form without n before spirants, both forms before other consonants, but often m before a labial: ĭn ＞ en (en amar, en cant), e (e Fransa, e ls), em (em breu); nōn ＞ non (non es, non ges), no (no falh, no tol), nom (nom plagues).
R remained: amātor ＞ amaire, cŏr ＞ cǫr, marmor ＞ marbre (marme shows dissimilation), sŏror ＞ sǫrre (sor through proclitic use). So in proclitics: per ＞ per, sŭper ＞ sọbre.