The verb fīō, fierī, factus sum belongs to two systems at once. It supplies the present-system passive of faciō “make, do,” but it also functions independently as “become” or “happen.” That combination explains why a form such as fit can mean “is made,” “becomes,” or “happens” even though its ending looks active.
This page gives the complete working paradigm and a parsing method. The construction is (neutral Classical); impersonal fit ut is especially common in (formal) prose, while poets may exploit unusual word order (literary) without changing the morphology.
Principal parts and the suppletive map
The active verb and its passive counterpart must be learned together:
| Function | Forms | Core meaning |
|---|---|---|
| active present system | faciō, facere | make, do |
| passive / inchoative present system | fīō, fierī | be made; become; happen |
| passive / inchoative perfect system | factus sum | was made; became; happened |
The relation is suppletive: different stems fill cells of what functions as one paradigm. English meaning cannot predict the stem. The principal parts tell you to use fī- in the present system and fact- with forms of sum in the perfect system.
Faber arcam facit; arca ex tabulīs fit.
The craftsman makes a chest; the chest is made from planks.
Present, imperfect, and future indicative
The present indicative has active-looking endings. Vowel quantity is part of the form: fīō, fīs, fīmus, fītis, and fīunt have long ī; fit has short i.
| Person | Present | Imperfect | Future |
|---|---|---|---|
| 1st singular | fīō | fīēbam | fīam |
| 2nd singular | fīs | fīēbās | fīēs |
| 3rd singular | fit | fīēbat | fīet |
| 1st plural | fīmus | fīēbāmus | fīēmus |
| 2nd plural | fītis | fīēbātis | fīētis |
| 3rd plural | fīunt | fīēbant | fīent |
The imperfect views an event as unfolding, repeated, or backgrounded; the future places it after the speech time. English often uses “was becoming,” “used to happen,” or “would be made” for fīēbat, so there is no one English label to substitute mechanically.
Dum cīvēs exspectant, pōns novus lentē fit.
While the citizens wait, the new bridge is slowly being built.
Adulēscēns cotidie prūdentior fīēbat.
The young man was becoming wiser every day.
Sī pecūnia aderit, bibliothēca prope forum fīet.
If the money is available, a library will be built near the forum.
The subjunctive and infinitive
The present subjunctive is fīam, fīās, fīat, fīāmus, fīātis, fīant. Its first-person singular fīam is identical to the future indicative, but other persons expose the contrast: future fīēs versus subjunctive fīās. The imperfect subjunctive is built transparently from the infinitive: fierem, fierēs, fieret, fierēmus, fierētis, fierent.
The present imperatives are fī (singular) and fīte (plural). They command the addressee to become something or, in a suitable passive context, to be made something; they do not restore an active meaning “make,” which belongs to fac and facite from faciō.
Rēx imperat ut portae ante noctem fīant.
The king orders that the gates be made before nightfall.
Utinam pāx ex tantā discordiā fieret!
If only peace might arise from such great discord!
The present infinitive fierī is passive in ending, unlike most finite forms. It appears in indirect statement and with modal verbs. In (formal) prose, fierī potest ut introduces a possible occurrence and takes a subjunctive ut-clause.
Legātī magnam mūtātiōnem fierī sentiunt.
The envoys perceive that a great change is taking place.
Fierī potest ut nūntius hodiē nōn veniat.
It is possible that the messenger may not come today.
Choosing among the three meanings
Use syntax rather than an English gloss. An affected nominative subject and an optional personal agent in ā/ab plus ablative favor the passive “be made/done.” A predicate nominative or adjective favors “become.” Impersonal fit, a clause as logical subject, or fit ut favors “happen.”
Haec statua ā sculptōre Rōmānō fit.
This statue is being made by a Roman sculptor.
Post longam hiemem diēs calidior fit.
After the long winter, the day grows warmer.
Interdum fit ut optimum cōnsilium vincat.
Sometimes it happens that the best plan prevails.
English “become” may suggest a preposition such as “into,” but Latin normally uses a predicate nominative: mīles fit “he becomes a soldier.” The nominative identifies the new status of the subject.
The perfect system
Perfect-system forms use an agreeing participle plus sum: factus sum, facta es, facta sunt. The perfect presents a completed transition or production; the pluperfect uses eram and the future perfect erō. An impersonal event uses neuter singular factum est “it happened.”
Cum ad portum vēnimus, nāvis iam facta erat.
When we reached the harbor, the ship had already been built.
Subitō factum est ut omnēs tacērent.
Suddenly it happened that everyone fell silent.
The visible participle makes gender and number unavoidable. Nāvēs factae sunt has feminine plural factae; English “the ships were made” shows no comparable agreement. This is ordinary Classical usage, not a stylistic option.
A reliable production test
Do not start from an English passive and assume that fīō supplies every Latin passive. For “the plans may be made,” cōnsilia is the receiver and present subjunctive third-person plural fīant gives cōnsilia fīant. For “the plans may be changed,” however, Latin uses the regular passive of mūtō: cōnsilia mūtentur. The phrase cōnsilia mūtāta fīant would instead make mūtāta a predicate, roughly “let the plans become changed.” Choose the Latin verb first, then build its own passive system.
The fuller passive relationship with faciō and the special behavior of compounds are treated on The Passive of faciō: fīō. The core diagnostic here remains the principal-part map.
Common Mistakes
1. Building a regular passive from faciō
❌ Nova lēx facitur.
Incorrect for the Classical present passive of faciō; facitur is an invented regular form here.
✅ Nova lēx fit.
A new law is being made.
2. Reading an active-looking ending as active voice
❌ Statua fit marmor.
Incorrect for ‘the statue makes marble’; fit does not supply the active meaning of faciō.
✅ Artifex statuam ex marmore facit.
The artist makes a statue from marble.
3. Carrying fī- into completed time
❌ Portae fīērunt ante noctem.
Incorrect as a perfect meaning; this treats the present-system stem as a perfect stem.
✅ Portae ante noctem factae sunt.
The gates were made before nightfall.
4. Translating every fit as “is made”
❌ Puer laetus fit. — Puer laetus fabricātur.
Incorrect interpretation; the predicate adjective signals a change of state, not manufacture.
✅ Puer laetus fit.
The boy becomes happy.
5. Confusing future and subjunctive fīam
❌ Crās fīam, ut pater iubet. — Subjunctive because the form ends in -am.
Incorrect reasoning; form alone does not settle the mood.
✅ Crās magister fīam; pater enim mē docuit.
Tomorrow I shall become a teacher; for my father taught me.
Key Takeaways
Fīō has active-looking finite endings but passive or inchoative meaning. Its present system uses fī-/fie-; its perfect system returns to agreeing factus plus sum. Parse tense and mood before translating, then let the construction choose among “be made,” “become,” and “happen.”
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