- Romanization of
- Forms the past participle of verbs.
- Forms adjectives having the sense "provided with".
The stem may be modified in certain predictable or unpredictable ways when this suffix is attached:
- Stem-final b and g are regularly devoiced to p and c respectively. If the stem ends in a short vowel and g, this vowel is usually lengthened (due to Lachmann's Law) but sometimes remains short (especially after the high vowel i, as in cōnstrictus from cōnstringō or fictus from fingō).
- A stem-final qu is delabialised, giving c.
- Stem-final v can become either u (forming a diphthong or long ū) or c. These are the expected outcomes of the distinct Proto-Italic consonants w and gʷ, respectively, which merged between vowels as Latin v. In actual fact, the outcome in Latin does not always correspond regularly to the original Proto-Italic consonant because of later analogical changes.
- A stem-final d or t fuses with the t of the suffix, giving -ssus. This is simplified to -sus if not preceded by a short vowel. Similarly to g-final stems, d-final stems sometimes (but not always) have lengthened vowels in the past participle due to Lachmann's Law.
- A stem-final rg also fuses with the t, giving -rsus.
- A stem final ll or rr sometimes fuses with the t, to -lsus and -rsus respectively.
- When attached to stems of 1st, 2nd or 4th conjugation verbs, the long stem-final vowel may be either retained unchanged, replaced by short -i-, or dropped entirely. It's retained for most 1st conjugation verbs, while it becomes short i for many 2nd conjugation verbs:
|Case / Gender||Masculine||Feminine||Neuter||Masculine||Feminine||Neuter|
-tus m (genitive -tūs); fourth declension
- Forms action nouns from verbs.
Same as for the participle suffix; see -sus.
- Forms collective/abstract nouns from adjectives or other nouns.
Same as for the participle suffix.