Deducir Conjugation in Spanish
The Spanish verb deducir means to deduce, and it is a verb you will use again and again once you know it. Deducir means to deduce, and it is used for working something out from clues, evidence or logic, as a detective does. It is a -ducir verb, with the present deduzco and the preterite deduje. Like every Spanish verb, deducir changes its ending for each person and tense, and this page gives you the complete picture: every tense, every person, the gerund and the past participle, all from the verified conjugation tables. For example, in the present tense you say deduzco la verdad de las pistas, and in the preterite you say deduje la respuesta del contexto. Work through the tables below, read the notes for each tense, and then test yourself with the examples, the common mistakes and the quiz at the end of the page.
Quick facts
- Infinitive: deducir
- English: to deduce
- Verb type: irregular verb
- Ending: -ir
- Gerund: deduciendo
- Past participle: deducido
- Auxiliary verb: haber (all perfect tenses are formed with haber + deducido)
Pronunciation is not listed on this page: the verified tables do not include IPA for deducir, so no pronunciation is given rather than an invented one. Deducir is a -ducir verb: the present is deduzco and the preterite is deduje. The subjunctive is deduzca.
Full conjugation tables
Every form below comes from the verified conjugation tables for deducir. The imperfect subjunctive is shown in its -ra forms; the -se forms use the same stem. For reflexive verbs, the pronoun column shows the reflexive pronoun that goes before each form.
Present indicative
| Person | Form |
|---|---|
| yo | deduzco |
| tú | deduces |
| él/ella/Ud. | deduce |
| nosotros/as | deducimos |
| vosotros/as | deducís |
| ellos/ellas/Uds. | deducen |
Preterite
| Person | Form |
|---|---|
| yo | deduje |
| tú | dedujiste |
| él/ella/Ud. | dedujo |
| nosotros/as | dedujimos |
| vosotros/as | dedujisteis |
| ellos/ellas/Uds. | dedujeron |
Imperfect
| Person | Form |
|---|---|
| yo | deducía |
| tú | deducías |
| él/ella/Ud. | deducía |
| nosotros/as | deducíamos |
| vosotros/as | deducíais |
| ellos/ellas/Uds. | deducían |
Future
| Person | Form |
|---|---|
| yo | deduciré |
| tú | deducirás |
| él/ella/Ud. | deducirá |
| nosotros/as | deduciremos |
| vosotros/as | deduciréis |
| ellos/ellas/Uds. | deducirán |
Conditional
| Person | Form |
|---|---|
| yo | deduciría |
| tú | deducirías |
| él/ella/Ud. | deduciría |
| nosotros/as | deduciríamos |
| vosotros/as | deduciríais |
| ellos/ellas/Uds. | deducirían |
Present perfect
| Person | Form |
|---|---|
| yo | he deducido |
| tú | has deducido |
| él/ella/Ud. | ha deducido |
| nosotros/as | hemos deducido |
| vosotros/as | habéis deducido |
| ellos/ellas/Uds. | han deducido |
Pluperfect
| Person | Form |
|---|---|
| yo | había deducido |
| tú | habías deducido |
| él/ella/Ud. | había deducido |
| nosotros/as | habíamos deducido |
| vosotros/as | habíais deducido |
| ellos/ellas/Uds. | habían deducido |
Future perfect
| Person | Form |
|---|---|
| yo | habré deducido |
| tú | habrás deducido |
| él/ella/Ud. | habrá deducido |
| nosotros/as | habremos deducido |
| vosotros/as | habréis deducido |
| ellos/ellas/Uds. | habrán deducido |
Conditional perfect
| Person | Form |
|---|---|
| yo | habría deducido |
| tú | habrías deducido |
| él/ella/Ud. | habría deducido |
| nosotros/as | habríamos deducido |
| vosotros/as | habríais deducido |
| ellos/ellas/Uds. | habrían deducido |
Present subjunctive
| Person | Form |
|---|---|
| yo | deduzca |
| tú | deduzcas |
| él/ella/Ud. | deduzca |
| nosotros/as | deduzcamos |
| vosotros/as | deducáis |
| ellos/ellas/Uds. | deduzcan |
Imperfect subjunctive (-ra)
| Person | Form |
|---|---|
| yo | dedujera |
| tú | dedujeras |
| él/ella/Ud. | dedujera |
| nosotros/as | dedujéramos |
| vosotros/as | dedujerais |
| ellos/ellas/Uds. | dedujeran |
Imperative (affirmative)
| Person | Form |
|---|---|
| tú | deduce |
| él/ella/Ud. | deduzca |
| nosotros/as | deduzcamos |
| vosotros/as | deducid |
| ellos/ellas/Uds. | deduzcan |
Imperative (negative)
| Person | Form |
|---|---|
| tú | deduzcas |
| él/ella/Ud. | deduzca |
| nosotros/as | deduzcamos |
| vosotros/as | deducáis |
| ellos/ellas/Uds. | deduzcan |
Gerund and past participle
| Form | Spanish | Use |
|---|---|---|
| Gerund | deduciendo | with estar for the progressive: estoy deduciendo |
| Past participle | deducido | with haber for the perfect tenses: he deducido |
How to use each tense
Present indicative
Use the present for routines, general facts and what is happening right now. This tense is irregular for this verb: it follows the pattern of the -ducir verbs, with a -zc- in the present (as in traduzco) and a -j- stem in the preterite (as in traduje). Learn the forms in the table rather than guessing them from the infinitive. For deducir, the present looks like this in a real sentence: Deduzco la verdad de las pistas. Learn the present forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Preterite
Use the preterite for finished actions with a clear end, often with ayer, el año pasado or anoche. This tense is irregular for this verb: it follows the pattern of the -ducir verbs, with a -zc- in the present (as in traduzco) and a -j- stem in the preterite (as in traduje). Learn the forms in the table rather than guessing them from the infinitive. For deducir, the preterite looks like this in a real sentence: Ayer, deduje el precio del descuento. Learn the preterite forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Imperfect
Use the imperfect for background, habits and actions in progress in the past, often with de niño, antes or mientras. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the imperfect looks like this in a real sentence: De niño, deducía la respuesta del contexto. Learn the imperfect forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Future
Use the future for plans, predictions and promises, often with mañana, el año que viene or pronto. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the future looks like this in a real sentence: Mañana, deduciré el resultado de los datos. Learn the future forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Conditional
Use the conditional for polite requests, hypotheticals and what would happen, often with si clauses. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the conditional looks like this in a real sentence: Deduciría la verdad de las pistas si pudiera. Learn the conditional forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Present perfect
Use the present perfect for recent actions and experiences, often with hoy, esta semana or ya. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the present perfect looks like this in a real sentence: Hoy, he deducido el precio del descuento. Learn the present perfect forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Pluperfect
Use the pluperfect when one past action happened before another past action. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the pluperfect looks like this in a real sentence: Había deducido la respuesta del contexto antes de salir. Learn the pluperfect forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Future perfect
Use the future perfect for something that will already be finished by a future time. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the future perfect looks like this in a real sentence: Para mañana, habré deducido el resultado de los datos. Learn the future perfect forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Conditional perfect
Use the conditional perfect for what would have happened under different conditions. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For deducir, the conditional perfect looks like this in a real sentence: Habría deducido la verdad de las pistas con más tiempo. Learn the conditional perfect forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Present subjunctive
Use the present subjunctive after expressions of wish, doubt, emotion and hope, such as espero que or quiero que. This tense is irregular for this verb: it follows the pattern of the -ducir verbs, with a -zc- in the present (as in traduzco) and a -j- stem in the preterite (as in traduje). Learn the forms in the table rather than guessing them from the infinitive. For deducir, the present subjunctive looks like this in a real sentence: Espero que él deduzca el precio del descuento. Learn the present subjunctive forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Imperfect subjunctive (-ra)
Use the imperfect subjunctive after past wishes and in si clauses about the past, and note the -ra forms shown here; the -se forms use the same stem. This tense is irregular for this verb: it follows the pattern of the -ducir verbs, with a -zc- in the present (as in traduzco) and a -j- stem in the preterite (as in traduje). Learn the forms in the table rather than guessing them from the infinitive. For deducir, the imperfect subjunctive looks like this in a real sentence: Si él dedujera la respuesta del contexto, todo cambiaría. Learn the imperfect subjunctive forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Imperative (affirmative)
Use the affirmative imperative for direct commands, instructions and invitations. This tense is irregular for this verb: it follows the pattern of the -ducir verbs, with a -zc- in the present (as in traduzco) and a -j- stem in the preterite (as in traduje). Learn the forms in the table rather than guessing them from the infinitive. For deducir, the affirmative imperative looks like this in a real sentence: ¡Deduce el resultado de los datos! Learn the affirmative imperative forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Imperative (negative)
Use the negative imperative, always with no, to tell someone not to do something. This tense is irregular for this verb: it follows the pattern of the -ducir verbs, with a -zc- in the present (as in traduzco) and a -j- stem in the preterite (as in traduje). Learn the forms in the table rather than guessing them from the infinitive. For deducir, the negative imperative looks like this in a real sentence: No deduzcas la verdad de las pistas. Learn the negative imperative forms in the table above alongside this example, and notice how the ending, not the stem, usually carries the meaning of the tense.
Example sentences
Ten natural sentences with deducir, covering different tenses and persons. Each one uses a form from the tables above.
- Deduzco la verdad de las pistas. — I deduce the truth from the clues.
- Deduce el precio del descuento. — He/she deduces the price from the discount.
- Ayer, deduje la respuesta del contexto. — Yesterday, I deduced the answer from the context.
- Antes, nosotros deducíamos el resultado de los datos. — Before, we used to deduce the result from the data.
- Mañana, tú deducirás la verdad de las pistas. — Tomorrow, you will deduce the truth from the clues.
- Yo deduciría el precio del descuento si tuviera más tiempo. — I would deduce the price from the discount if I had more time.
- Él ha deducido la respuesta del contexto. — He has deduced the answer from the context.
- Espero que él deduzca el resultado de los datos. — I hope he deduces the result from the data.
- Yo ya había deducido la verdad de las pistas antes de salir. — I had already deduced the truth from the clues before leaving.
- Ellos deducían el precio del descuento cuando eran jóvenes. — They used to deduce the price from the discount when they were young.
Common mistakes
- Wrong: Yo deduce la verdad de las pistas. — Right: Yo deduzco la verdad de las pistas. — The person matters: deduce is the él/ella/Ud. form, while the yo form is deduzco. Using the third-person form with yo is one of the most common beginner errors.
- Wrong: Ayer yo deducí el precio del descuento. — Right: Ayer yo deduje el precio del descuento. — Deducir has an irregular preterite: the correct first-person form is deduje, not the regular deducí. Learn the preterite forms in the table as a set.
- Wrong: Treating deducir and inferir as identical in every context. — Right: Deducir means to deduce, while inferir means to infer. — They overlap, but each has uses the other does not: deducir fits sentences such as Deduzco la verdad de las pistas, while inferir belongs in a different sentence. Check the meaning you want before choosing.
- Wrong: Yo soy deducido el precio del descuento. — Right: Yo he deducido el precio del descuento. — Spanish perfect tenses use haber, not ser: he deducido, has deducido, ha deducido. Ser plus the participle makes a passive, not a perfect tense.
- Wrong: De niño, yo deduje la respuesta del contexto todos los días. — Right: De niño, yo deducía la respuesta del contexto todos los días. — For a repeated habit in the past, use the imperfect (deducía), not the preterite. The preterite (deduje) is for one finished action.
Quiz: test yourself
Ten questions on deducir. Choose the right form, then check the answer key below.
Complete the sentence: Yo ___ la verdad de las pistas. (present tense) A. deduzco B. deduces C. deduce D. deducimos
Complete the sentence: Ayer, él ___ el precio del descuento. (preterite) A. deduje B. dedujiste C. dedujeron D. dedujo
Complete the sentence: Antes, nosotros ___ la respuesta del contexto. (imperfect) A. deducías B. deducían C. deducíamos D. deducía
Complete the sentence: Mañana, tú ___ el resultado de los datos. (future) A. deduciremos B. deducirás C. deduciré D. deducirá
Complete the sentence: Yo ___ la verdad de las pistas si pudiera. (conditional) A. deduciría B. deducirías C. deducirían D. deduzco
Complete the sentence: Espero que él ___ el precio del descuento. (present subjunctive) A. deduzcas B. deduzcamos C. deduzco D. deduzca
Complete the sentence: Si yo ___ la respuesta del contexto, todo cambiaría. (imperfect subjunctive, -ra form) A. dedujéramos B. deduzco C. dedujera D. dedujeras
Complete the sentence: Nosotros ___ el resultado de los datos. (present perfect) A. han deducido B. hemos deducido C. he deducido D. has deducido
Complete the command: ¡___ la verdad de las pistas! (affirmative imperative, tú) A. deduce B. deduzca C. deduzcamos D. deducid
Which is the gerund of deducir, used with estar for the progressive? A. deducido B. deduzco C. deduje D. deduciendo
Answer key
- deduzco — The first-person present of deducir is deduzco. The other options are the tú, él/ella and nosotros forms.
- dedujo — The third-person preterite of deducir is dedujo, the form for a single finished action in the past.
- deducíamos — The nosotros imperfect of deducir is deducíamos, used here for a repeated past habit.
- deducirás — The second-person future of deducir is deducirás.
- deduciría — The first-person conditional of deducir is deduciría, the form for what would happen.
- deduzca — After espero que, the subjunctive is required: the third-person present subjunctive of deducir is deduzca.
- dedujera — The first-person imperfect subjunctive (-ra) of deducir is dedujera.
- hemos deducido — The nosotros present perfect of deducir is hemos deducido: hemos + deducido.
- deduce — The affirmative tú imperative of deducir is deduce.
- deduciendo — The gerund of deducir is deduciendo: estoy deduciendo. The participle deducido is used with haber instead.
Frequently asked questions
What does deducir mean in English?
Deducir means to deduce. It is used in everyday situations such as Deduzco la verdad de las pistas. The exact English wording depends on the context, but the core meaning stays the same across the tenses.
Is deducir regular or irregular?
Deducir is irregular in present, preterite, present-subjunctive, imperfect-subjunctive, imperative-affirmative, imperative-negative. The other tenses follow the regular pattern. Learn the irregular forms from the tables above rather than guessing them from the infinitive.
What is the difference between deducir and inferir?
Deducir means to deduce, while inferir means to infer. They are easy to confuse because they appear in similar situations, but they are not interchangeable: use deducir when you mean to deduce, as in Deduzco la verdad de las pistas, and use inferir for to infer. When in doubt, check the object of the sentence — it usually shows which verb fits.
How do I say “I deduce” in the past?
It depends on the kind of past. For one finished action, use the preterite: yo deduje el precio del descuento. For a repeated habit or background in the past, use the imperfect: yo deducía la respuesta del contexto. For something that has just happened, use the present perfect: yo he deducido el precio del descuento.
How do I practise deducir?
Start with the present tense table, then drill the preterite and the imperfect, since those two past tenses cause the most mistakes. Try the deducir examples and quiz page for more sentences, and use the Spanish Verb Quiz to test the forms under pressure.
Related links
- Deducir in the preterite tense — the full preterite-tense table for deducir.
- Deducir examples and quiz — more example sentences and practice for deducir.
- Spanish verbs — the Spanish hub, with every verb and tense guide.
- Complete list of Spanish irregular verbs — where this verb's pattern is listed.
- Introducir conjugation — another -ir verb to compare with deducir.
- Traducir conjugation — another -ir verb to compare with deducir.
- Contradecir conjugation — another -ir verb to compare with deducir.
- Spanish Verb Conjugator — conjugate any Spanish verb in every tense.
- Spanish Verb Quiz — test yourself on real conjugated forms.