Oscurecer Conjugation in Spanish

The Spanish verb oscurecer means to get dark, and it is a verb you will use again and again once you know it. Oscurecer means to get dark, and it is used for the sky darkening before a storm, a room darkening and the day darkening in winter. It is mostly used in the third person, and it is a -cer spelling-change verb. Anochecer is its close synonym for nightfall. Like every Spanish verb, oscurecer 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 oscurezco muy pronto en invierno, and in the preterite you say oscurecí la habitación al cerrar las cortinas. 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: oscurecer
  • English: to get dark
  • Verb type: irregular verb
  • Ending: -er
  • Gerund: oscureciendo
  • Past participle: oscurecido
  • Auxiliary verb: haber (all perfect tenses are formed with haber + oscurecido)

Pronunciation is not listed on this page: the verified tables do not include IPA for oscurecer, so no pronunciation is given rather than an invented one. Spelling change: c becomes zc before o and a, so yo oscurezco and the subjunctive oscurezca. It is mostly used in the third person.

Full conjugation tables

Every form below comes from the verified conjugation tables for oscurecer. 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 oscurezco
tú oscureces
él/ella/Ud. oscurece
nosotros/as oscurecemos
vosotros/as oscurecéis
ellos/ellas/Uds. oscurecen

Preterite

Person Form
yo oscurecí
tú oscureciste
él/ella/Ud. oscureció
nosotros/as oscurecimos
vosotros/as oscurecisteis
ellos/ellas/Uds. oscurecieron

Imperfect

Person Form
yo oscurecía
tú oscurecías
él/ella/Ud. oscurecía
nosotros/as oscurecíamos
vosotros/as oscurecíais
ellos/ellas/Uds. oscurecían

Future

Person Form
yo oscureceré
tú oscurecerás
él/ella/Ud. oscurecerá
nosotros/as oscureceremos
vosotros/as oscureceréis
ellos/ellas/Uds. oscurecerán

Conditional

Person Form
yo oscurecería
tú oscurecerías
él/ella/Ud. oscurecería
nosotros/as oscureceríamos
vosotros/as oscureceríais
ellos/ellas/Uds. oscurecerían

Present perfect

Person Form
yo he oscurecido
tú has oscurecido
él/ella/Ud. ha oscurecido
nosotros/as hemos oscurecido
vosotros/as habéis oscurecido
ellos/ellas/Uds. han oscurecido

Pluperfect

Person Form
yo había oscurecido
tú habías oscurecido
él/ella/Ud. había oscurecido
nosotros/as habíamos oscurecido
vosotros/as habíais oscurecido
ellos/ellas/Uds. habían oscurecido

Future perfect

Person Form
yo habré oscurecido
tú habrás oscurecido
él/ella/Ud. habrá oscurecido
nosotros/as habremos oscurecido
vosotros/as habréis oscurecido
ellos/ellas/Uds. habrán oscurecido

Conditional perfect

Person Form
yo habría oscurecido
tú habrías oscurecido
él/ella/Ud. habría oscurecido
nosotros/as habríamos oscurecido
vosotros/as habríais oscurecido
ellos/ellas/Uds. habrían oscurecido

Present subjunctive

Person Form
yo oscurezca
tú oscurezcas
él/ella/Ud. oscurezca
nosotros/as oscurezcamos
vosotros/as oscurecáis
ellos/ellas/Uds. oscurezcan

Imperfect subjunctive (-ra)

Person Form
yo oscureciera
tú oscurecieras
él/ella/Ud. oscureciera
nosotros/as oscureciéramos
vosotros/as oscurecierais
ellos/ellas/Uds. oscurecieran

Imperative (affirmative)

Person Form
tú oscurece
él/ella/Ud. oscurezca
nosotros/as oscurezcamos
vosotros/as oscureced
ellos/ellas/Uds. oscurezcan

Imperative (negative)

Person Form
tú oscurezcas
él/ella/Ud. oscurezca
nosotros/as oscurezcamos
vosotros/as oscurecáis
ellos/ellas/Uds. oscurezcan

Gerund and past participle

Form Spanish Use
Gerund oscureciendo with estar for the progressive: estoy oscureciendo
Past participle oscurecido with haber for the perfect tenses: he oscurecido

How to use each tense

Present indicative

Use the present for routines, general facts and what is happening right now. Note the spelling change here: c becomes zc before o and a, so the forms keep the same sound as the infinitive. For oscurecer, the present looks like this in a real sentence: Oscurezco muy pronto en invierno. 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. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For oscurecer, the preterite looks like this in a real sentence: Ayer, oscurecí el cielo antes de la tormenta. 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 oscurecer, the imperfect looks like this in a real sentence: De niño, oscurecía la habitación al cerrar las cortinas. 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 oscurecer, the future looks like this in a real sentence: Mañana, oscureceré sobre el campo al final del día. 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 oscurecer, the conditional looks like this in a real sentence: Oscurecería muy pronto en invierno 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 oscurecer, the present perfect looks like this in a real sentence: Hoy, he oscurecido el cielo antes de la tormenta. 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 oscurecer, the pluperfect looks like this in a real sentence: Había oscurecido la habitación al cerrar las cortinas 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 oscurecer, the future perfect looks like this in a real sentence: Para mañana, habré oscurecido sobre el campo al final del día. 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 oscurecer, the conditional perfect looks like this in a real sentence: Habría oscurecido muy pronto en invierno 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. Note the spelling change here: c becomes zc before o and a, so the forms keep the same sound as the infinitive. For oscurecer, the present subjunctive looks like this in a real sentence: Espero que él oscurezca el cielo antes de la tormenta. 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. For this verb the tense is regular, so the forms follow the standard endings for its verb class. For oscurecer, the imperfect subjunctive looks like this in a real sentence: Si él oscureciera la habitación al cerrar las cortinas, 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. Note the spelling change here: c becomes zc before o and a, so the forms keep the same sound as the infinitive. For oscurecer, the affirmative imperative looks like this in a real sentence: ¡Oscurece sobre el campo al final del día! 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. Note the spelling change here: c becomes zc before o and a, so the forms keep the same sound as the infinitive. For oscurecer, the negative imperative looks like this in a real sentence: No oscurezcas muy pronto en invierno. 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 oscurecer, covering different tenses and persons. Each one uses a form from the tables above.

  1. Oscurezco muy pronto en invierno. — I get dark very early in winter.
  2. Oscurece el cielo antes de la tormenta. — He/she gets dark the sky before the storm.
  3. Ayer, oscurecí la habitación al cerrar las cortinas. — Yesterday, I got dark the room on closing the curtains.
  4. Antes, nosotros oscurecíamos sobre el campo al final del día. — Before, we used to get dark over the fields at the end of the day.
  5. Mañana, tú oscurecerás muy pronto en invierno. — Tomorrow, you will get dark very early in winter.
  6. Yo oscurecería el cielo antes de la tormenta si tuviera más tiempo. — I would get dark the sky before the storm if I had more time.
  7. Él ha oscurecido la habitación al cerrar las cortinas. — He has got dark the room on closing the curtains.
  8. Espero que él oscurezca sobre el campo al final del día. — I hope he gets dark over the fields at the end of the day.
  9. Yo ya había oscurecido muy pronto en invierno antes de salir. — I had already got dark very early in winter before leaving.
  10. Ellos oscurecían el cielo antes de la tormenta cuando eran jóvenes. — They used to get dark the sky before the storm when they were young.

Common mistakes

  1. Wrong: Yo oscurece muy pronto en invierno. — Right: Yo oscurezco muy pronto en invierno. — The person matters: oscurece is the él/ella/Ud. form, while the yo form is oscurezco. Using the third-person form with yo is one of the most common beginner errors.
  2. Wrong: Yo oscureco el cielo antes de la tormenta. — Right: Yo oscurezco el cielo antes de la tormenta. — In the present, the correct first-person form is oscurezco, not oscureco. oscurecer is a spelling-change verb: c becomes zc before o and a, so the written form changes to keep the same sound. The regular-looking form is wrong.
  3. Wrong: Treating oscurecer and amanecer as identical in every context. — Right: Oscurecer means to get dark, while amanecer means to dawn, its opposite. — They overlap, but each has uses the other does not: oscurecer fits sentences such as Oscurezco muy pronto en invierno, while amanecer belongs in a different sentence. Check the meaning you want before choosing.
  4. Wrong: Yo soy oscurecido el cielo antes de la tormenta. — Right: Yo he oscurecido el cielo antes de la tormenta. — Spanish perfect tenses use haber, not ser: he oscurecido, has oscurecido, ha oscurecido. Ser plus the participle makes a passive, not a perfect tense.
  5. Wrong: De niño, yo oscurecí la habitación al cerrar las cortinas todos los días. — Right: De niño, yo oscurecía la habitación al cerrar las cortinas todos los días. — For a repeated habit in the past, use the imperfect (oscurecía), not the preterite. The preterite (oscurecí) is for one finished action.

Quiz: test yourself

Ten questions on oscurecer. Choose the right form, then check the answer key below.

  1. Complete the sentence: Yo ___ muy pronto en invierno. (present tense) A. oscurezco B. oscureces C. oscurece D. oscurecemos

  2. Complete the sentence: Ayer, él ___ el cielo antes de la tormenta. (preterite) A. oscurecí B. oscureciste C. oscurecieron D. oscureció

  3. Complete the sentence: Antes, nosotros ___ la habitación al cerrar las cortinas. (imperfect) A. oscurecías B. oscurecían C. oscurecíamos D. oscurecía

  4. Complete the sentence: Mañana, tú ___ sobre el campo al final del día. (future) A. oscureceremos B. oscurecerás C. oscureceré D. oscurecerá

  5. Complete the sentence: Yo ___ muy pronto en invierno si pudiera. (conditional) A. oscurecería B. oscurecerías C. oscurecerían D. oscurezco

  6. Complete the sentence: Espero que él ___ el cielo antes de la tormenta. (present subjunctive) A. oscurezcas B. oscurezcamos C. oscurezco D. oscurezca

  7. Complete the sentence: Si yo ___ la habitación al cerrar las cortinas, todo cambiaría. (imperfect subjunctive, -ra form) A. oscureciéramos B. oscurezco C. oscureciera D. oscurecieras

  8. Complete the sentence: Nosotros ___ sobre el campo al final del día. (present perfect) A. han oscurecido B. hemos oscurecido C. he oscurecido D. has oscurecido

  9. Complete the command: ¡___ muy pronto en invierno! (affirmative imperative, tú) A. oscurece B. oscurezca C. oscurezcamos D. oscureced

  10. Which is the gerund of oscurecer, used with estar for the progressive? A. oscurecido B. oscurezco C. oscurecí D. oscureciendo

Answer key

  1. oscurezco — The first-person present of oscurecer is oscurezco. The other options are the tú, él/ella and nosotros forms.
  2. oscureció — The third-person preterite of oscurecer is oscureció, the form for a single finished action in the past.
  3. oscurecíamos — The nosotros imperfect of oscurecer is oscurecíamos, used here for a repeated past habit.
  4. oscurecerás — The second-person future of oscurecer is oscurecerás.
  5. oscurecería — The first-person conditional of oscurecer is oscurecería, the form for what would happen.
  6. oscurezca — After espero que, the subjunctive is required: the third-person present subjunctive of oscurecer is oscurezca.
  7. oscureciera — The first-person imperfect subjunctive (-ra) of oscurecer is oscureciera.
  8. hemos oscurecido — The nosotros present perfect of oscurecer is hemos oscurecido: hemos + oscurecido.
  9. oscurece — The affirmative tú imperative of oscurecer is oscurece.
  10. oscureciendo — The gerund of oscurecer is oscureciendo: estoy oscureciendo. The participle oscurecido is used with haber instead.

Frequently asked questions

What does oscurecer mean in English?

Oscurecer means to get dark. It is used in everyday situations such as Oscurezco muy pronto en invierno. The exact English wording depends on the context, but the core meaning stays the same across the tenses.

Is oscurecer regular or irregular?

Oscurecer is a fully regular -er verb, so every tense follows the standard endings for its class. Once you know the regular pattern, you can produce every form on this page, including oscurezco in the present and oscurecí in the preterite.

What is the difference between oscurecer and amanecer?

Oscurecer means to get dark, while amanecer means to dawn, its opposite. They are easy to confuse because they appear in similar situations, but they are not interchangeable: use oscurecer when you mean to get dark, as in Oscurezco muy pronto en invierno, and use amanecer for to dawn, its opposite. When in doubt, check the object of the sentence — it usually shows which verb fits.

How do I say “I get dark” in the past?

It depends on the kind of past. For one finished action, use the preterite: yo oscurecí el cielo antes de la tormenta. For a repeated habit or background in the past, use the imperfect: yo oscurecía la habitación al cerrar las cortinas. For something that has just happened, use the present perfect: yo he oscurecido el cielo antes de la tormenta.

How do I practise oscurecer?

Start with the present tense table, then drill the preterite and the imperfect, since those two past tenses cause the most mistakes. Try the oscurecer examples and quiz page for more sentences, and use the Spanish Verb Quiz to test the forms under pressure.

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