Compounds of Fīō

Compounds of faciō vary between passives in -fīō and passives in -ficior. The distinction? Check the vowel a (faciō) in the compound. In the rare case that this is retain in the compound, then –fīō is also retained.

benefaciō, benefacere, benefēcī, benefactum (in place of the expected beneficio/ficere/fēcī/fectum, and hence the English ‘benefaction’ but also ‘infection.’)

  • benefīō, benefierī, benefactus sum

Several of the faciō compounds that feature -ficiō/-ficior forms will also feature passive -fīō forms, with separate meanings.

  • cōnfit, it happens
  • dēfit, it lacks
  • īnfit, he beings (to speak)
  • interfit, he perishes
  • superfit, there remains

The Essential AG: 204b-c