possum
From Proto-Italic *possom, from *potis (“master in control of”) + *som (“I am”). Cognates include Oscan púttiad (“they can”) and South Picene puti (“I could”).
Pronunciation
- (Classical) IPA(key): /ˈpos.sum/, [ˈpɔs̠ːʊ̃ˑ]
- (modern Italianate Ecclesiastical) IPA(key): /ˈpos.sum/, [ˈpɔsːum]
Verb
possum (present infinitive posse, perfect active potuī); irregular conjugation, irregular, no passive
Conjugation
This verb is irregular, but synchronously resembles sum prefixed with pot-. Several contractions and simplifications occur, however, namely: -ts- → -ss-, -tf- → -t-, -tess- → -ss- (note that potēns does not originate from non-existent *fēns).
However, while this analysis works synchronically, diachronically, this relationship does not reflect a cognate historical relationship in all cases. For example, Osco-Umbrian forms confirm that a Proto-Italic verb Proto-Italic *poteō (“to be master”) (stem *pot-ē-) must also be reconstructed that, although lost in Latin otherwise, appears to have been the ultimate historical source of potuī and potēns.[1]
In Vulgar Latin, the first person singular is changed to possō (causing the verb to be treated like a third conjugation verb (base poss-) in the present subjunctive (*possam, *possās)), while the third person plural (eī/eae/ea) possunt was preserved as such, though the rest of the verb became the second conjugation verb potēre ((tu) *potēs, (is/ea/id) *potet, (nōs) *potēmus and (vōs) *potētis), based on forms like potuī and potēns, just like velle (infinitive of volō) was reformed to *volēre after forms like voluī and volēns.