Verbs Ending in -uzir

Verbs whose infinitive ends in -uzir form one of the tightest, most predictable verb classes in European Portuguese. Every member behaves identically. Once you know produzir (to produce), you know conduzir (to drive), traduzir (to translate), reduzir (to reduce), introduzir (to introduce), deduzir (to deduce), seduzir (to seduce), induzir (to induce), and a handful of less frequent verbs besides. The class has a single distinctive feature: the 3sg present indicative drops its expected -e ending and ends in a bare consonant. So produz (he/she produces), not produze. This tiny truncation is the whole irregularity. Every other form is a plain -ir verb.

The core pattern: a truncated 3sg

In regular -ir verbs, the 3sg present indicative ends in -e: partir → parte, abrir → abre, decidir → decide. The -uzir verbs break this pattern. Their 3sg ends in the stem consonant -z with no final vowel: produz, conduz, traduz, reduz, introduz. The truncation is historical and distinctive enough that it became a teaching point on its own.

Produzir (to produce) — full paradigm

Present indicative

Notice the 3sg produz — bare stem, no final -e. Compare with the 2sg produzes and the 3pl produzem, which keep their full vowel endings.

Present subjunctive

The subjunctive is fully regular. No truncation — that is a present-indicative-only phenomenon.

Preterite

Fully regular -ir preterite. No truncation, no accent tricks.

Imperfect

Produzia, produzias, produzia, produzíamos, produziam. Regular.

Future and conditional

• Future: produzirei, produzirás, produzirá, produziremos, produzirão.
• Conditional: produziria, produzirias, produziria, produziríamos, produziriam.

All regular.

Imperative

The affirmative tu imperative = 3sg present indicative = produz (truncated). Every other imperative form uses the subjunctive and is regular:

• Affirmative tu: produz.
• Negative tu: não produzas.
• Affirmative você / vocês: produza, produzam.
• Negative você / vocês: não produza, não produzam.

The truncated imperative produz is also what you see on road signs and in instructions: Conduz com cuidado! ("Drive carefully!").

Past participle and gerund

• Past participle: produzido (regular).
• Gerund: produzindo (regular).

Conduzir (to drive / to conduct)

Same paradigm, stem conduz-.

In European Portuguese, conduzir is the standard verb for "to drive a vehicle." Brazilian Portuguese prefers dirigir, which has a different meaning in PT-PT ("to manage, to direct"). Do not substitute dirigir for conduzir in Portugal.

Traduzir (to translate)

Reduzir, Introduzir, Deduzir, Seduzir, Induzir

All follow the identical pattern. A summary table of the distinctive present-indicative forms:

Why the truncation?

A short historical note. In older Portuguese, the 3sg of these verbs was produze, conduze, traduze, following the regular -ir pattern. Over time, the final -e eroded in a specific group of verbs whose stems ended in -z — producing produz, conduz, and so on. The same erosion affected a handful of other verbs outside the -uzir class: fazer → faz, dizer → diz, trazer → traz. In all of these, the bare final consonant is a trace of an earlier full form.

The erosion did not happen in the 2sg or 3pl because those forms still carry a following consonant (-s, -m), which prevented the vowel from dropping. It also did not happen in the subjunctive, where the -a ending sits in a different morphological position.

So the 3sg truncation is a one-off historical change, preserved and now regularized as the "rule" for -uzir verbs. It is a fact about the spelling, not a productive phonological process — and the rest of the paradigm remains entirely regular.

Spelling consistency across tenses

Note that the stem -z- is preserved in every form — there is no spelling change to -c- or -ç-. The /z/ sound of the infinitive is /z/ throughout the paradigm, and Portuguese writes it with z in every position.

This is a nice contrast with -çar verbs where the cedilla drops before -e or -i (começar → comece). In -uzir verbs, no such spelling adjustment is needed because z is already consistent with all following vowels.

Comparison with Spanish

Spanish has cognate verbs: producir, conducir, traducir, reducir, introducir, deducir, seducir, inducir. The Spanish conjugation is more irregular than the Portuguese one:

• Spanish 1sg: produzco, conduzco, traduzco, reduzco... — with an inserted -zc- before the -o ending. Portuguese: produzo, conduzo, traduzo — just -z- plus -o.
• Spanish present subjunctive: produzca, produzcas, produzca... — with -zc- throughout. Portuguese: produza, produzas, produza — plain -z-.
• Spanish preterite: produje, produjiste, produjo, produjimos, produjeron — a strong preterite with -j- replacing -z-. Portuguese: produzi, produziste, produziu, produzimos, produziram — fully regular with -z- throughout.

Spanish speakers cross-learning Portuguese will find this class much simpler than its Spanish equivalent — no -zc- insertion, no strong preterite. Just drop the 3sg -e and you are done.

English-speakers' angle

English has no systematic analogue. The truncation in produz is a visual adjustment — a missing letter — that has no parallel in English conjugation. The best mental model is: "the 3sg drops the -e that other verbs keep." Read and say produz (one syllable) rather than produze (two syllables), and the pattern becomes second nature.

One helpful analogy: the English verbs has and does also have truncated 3sg forms compared to the hypothetical full pattern hases or doeses. Portuguese -uzir verbs do something roughly similar — a short-form 3sg that looks truncated compared to the pattern of the rest of the class.

Common Mistakes

Key takeaways

• The -uzir class includes produzir, conduzir, traduzir, reduzir, introduzir, deduzir, seduzir, induzir, reproduzir, aduzir, and their compounds.
• The single distinctive feature is the 3sg present indicative: it drops the expected -e ending and becomes bare -z. So produz, conduz, traduz, reduz, introduz.
• The truncation carries over into the affirmative tu imperative (since that form copies the 3sg): Conduz com cuidado! Traduz esta frase!
• Every other form — 1sg, 2sg, 3pl, all subjunctive forms, all preterite, imperfect, future, conditional, past participle, gerund — is fully regular.
• Do not import Spanish patterns: Portuguese has no -zc- insertion (produzo, not produzco) and no strong preterite (produziu, not produjo).
• The z stem is preserved across all forms with no spelling changes.