The variety in form in the Nominative is due to simple modifications of the stem, of which the most important are -
1. Combination of final consonants: as of c (or g) and s to form x; dux.
2. Omission of a final consonant: as of a final nasal; leó, leónis, stem león-; órátió, órátiónis, stem órátión-.
3. Omission of a final vowel: as of final i; calcar, calcáris, stem calcári-.
4. Change of a vowel in the final syllable: as of a to e; prínceps (for -caps), príncipis, stem príncip- (for -cap-).