[2445.] (a.) Final i is short in nisi, quasi, and sīcuti; also in the endings of some Greek nouns: as N. and Ac. sināpi; V. Pari, Amarylli; D. Paridi, Minōidi; Pl. D. Trōasi.
[2446.] (b.) Final i is common in mihī̆, tibī̆, sibī̆; ibī̆, ubī̆ ([129, 2]).
[(2.) Ending in a Single Consonant not s.]
[2447.] A final syllable ending in a single consonant not s has its vowel short: as,
dōnec. illud. animal ([536]); semel. agmen. calcar ([537]); soror, stultior ([132]). moror, loquar, fatēbor ([132]); regitur, regimur, reguntur. regit ([826]); amat, sciat, pōnēbat; tinnit, possit; iacet, neget, esset ([132]).
Exceptions.
[2448.] (a.) The last vowel is long in allēc, and in compounds of pār; in the contracted genitive plural of stems in -u-: as currūm; in all cases of illic and istic except the nominative masculine, in the adverbs illūc and istūc, and sometimes in nihī̆l. Also in the endings of some Greek nouns: as, N. āēr, aethēr, sīrēn; Ac. Aenēān.
[2449.] (b.) In the short form of the genitive plural of stems in -o- and -ā-, the vowel was originally long, but afterwards short: as, dīvŏ̄m ([462]), caelicolū̆m ([439]).
[2450.] (c.) The last vowel is long in iīt and petiīt and their compounds.