N, n, had its full, pure sound only when it began a syllable; in the middle or at the end of a word it was weakened. Hence the remark of Priscian (p. 556 P.):
n quoque plenior in primis sonat, et in ultimis partibus syllabarum, ut nomen, stamen; exilior in mediis, ut amnis, damnum, is not accurate, v. Corss. Ausspr. 1, p. 248 sq. Between two vowels, the single n frequently takes the place, in MSS. and inscriptions, of double n; thus: Pescenius, Porsena, conubium, conecto, conitor, coniveo. The n of con- for com- often falls away before h; as: cohaerere, coheres, cohibere, cohors; and before j; as: coicere, cojux or cojunx, cosul, etc. In very late Latin, n was frequently dropped before s in the participial ending -ans, -ens, and before st, scr , or simple s in composition. In the earlier language this occurs in the ending -iens; as: quoties, toties, vicies, for quotiens, etc.; and in a few other instances, as castresis for castrensis; formosus for the older form formonsus; and in inscriptions, meses for menses, tösor for tonsor, etc.; cf. also, quăsi for quansi (quam si). Before the guttural letters a medial n receives the sound of Greek γ before gutturals, wherefore, in early times, viz., by Attius, we have also g written for n : Agchises, agceps, aggulus, aggens, agguilla, iggerunt, etc., Varr. ap. Prisc. p. 556 P. (cf. Varr. L. L. p. 264 Müll.); cf. Mar. Victor. p. 2462 and 2465 P.; hence called n adulterinum by Nigid. ap. Gell. 19, 14, 7.Assimilation commonly takes place before l, m , and r : illabor, immitto, irrumpo (v. in ), yet is often neglected; before the labials, n is commonly changed into m : imberbis, imbutus; impar, impleo; and before initial m the preposition in is frequently written im , v. Prol. Verg. p. 433 Rib.The letter n is frequently inserted , particularly before s : me n sis, e n sis, ansa; Megalesia and Megalensia, frons and frus. Less freq. before other consonants: tu n do, ju n go, mi n go, pu n go, etc.; cf. also: lanterna and laterna, ligula and lingula. Sometimes n is inserted with a vowel: fru-niscor from fruor, and perh. fenestra from festra. The double forms, alioquin and alioqui, ceteroqui and ceteroquin, seem to rest on purely phonetic grounds, v. h. vv.As an abbreviation, N usually stands for natus, nefastus dies, nepos, nomine, novum, the praenomen Numerius, numero, numine.—N = natione, natus, nostri, nostro, etc., numerus, numero, etc. N. D. N. = numini domini nostri. N. L. = non liquet (v. liqueo). N. M. V. = nobilis memoriae vir. NN. BB. = nobilissimi. NP. = nefastus prior. NVM. = nummum. In poetry, n alone sometimes stands for the enclitic ne , even before a consonant: nostin quae sit? Ter. Eun. 349; Verg. A. 3, 319; 12, 797 al.