Introduction
Comenzar means «to begin, to start». Comenzar means to begin or to start: to study, a job, a film, on Monday. It is an e → ie stem-changing verb (comienzo, comienzas) with a spelling change too: before an e, the z becomes c, so the yo preterite is comencé. It is a irregular -ar verb, stem-changing (e → ie), so the tables below show you exactly how it behaves in every tense. On this page you will find the full conjugation of comenzar in all thirteen tenses, notes on when to use each one, example sentences, the mistakes learners make most often, a ten-question quiz and answers to the questions students ask about this verb. For example: «Yo comienzo a estudiar todos los días.» — I begin to study every day.
Quick facts
| Infinitive | comenzar |
| English | to begin, to start |
| Verb type | Irregular -ar verb, stem-changing (e → ie) |
| Gerund | comenzando |
| Past participle | comenzado |
| Auxiliary verb | haber |
Full conjugation tables
Gerund: comenzando · Past participle: comenzado
Present Indicative
| Person | Form |
|---|---|
| yo | comienzo |
| tú | comienzas |
| él/ella/Ud. | comienza |
| nosotros/as | comenzamos |
| vosotros/as | comenzáis |
| ellos/ellas/Uds. | comienzan |
The present tense describes habits, facts and what is happening now. For comenzar, the yo form is comienzo, as in «Yo comienzo» in the examples below. This is one of the tenses where comenzar does not follow the regular -ar pattern, so learn the forms in the table above rather than guessing them from the infinitive. Use the present for routines («todos los días») and for general truths.
Preterite
| Person | Form |
|---|---|
| yo | comencé |
| tú | comenzaste |
| él/ella/Ud. | comenzó |
| nosotros/as | comenzamos |
| vosotros/as | comenzasteis |
| ellos/ellas/Uds. | comenzaron |
The preterite describes completed actions in the past — things that started and finished. «Ayer yo comencé» is the classic use. Do not confuse it with the imperfect: the preterite moves the story forward, one finished event at a time.
Imperfect
| Person | Form |
|---|---|
| yo | comenzaba |
| tú | comenzabas |
| él/ella/Ud. | comenzaba |
| nosotros/as | comenzábamos |
| vosotros/as | comenzabais |
| ellos/ellas/Uds. | comenzaban |
The imperfect describes the past as background: habits, descriptions and actions in progress. «De pequeño, yo comenzaba» shows the habitual use. It sets the scene while the preterite reports what happened inside it.
Future
| Person | Form |
|---|---|
| yo | comenzaré |
| tú | comenzarás |
| él/ella/Ud. | comenzará |
| nosotros/as | comenzaremos |
| vosotros/as | comenzaréis |
| ellos/ellas/Uds. | comenzarán |
The future tense states what will happen. For comenzar the future is built on the infinitive: «Mañana yo comenzaré». It is also used for predictions and promises, and in spoken Spanish it often alternates with ir a + infinitive.
Conditional
| Person | Form |
|---|---|
| yo | comenzaría |
| tú | comenzarías |
| él/ella/Ud. | comenzaría |
| nosotros/as | comenzaríamos |
| vosotros/as | comenzaríais |
| ellos/ellas/Uds. | comenzarían |
The conditional expresses what would happen: wishes, polite requests and hypothetical results. «Si tuviera más tiempo, yo comenzaría» is the typical pattern. It shares its stem with the future and changes only the endings.
Present Perfect
| Person | Form |
|---|---|
| yo | he comenzado |
| tú | has comenzado |
| él/ella/Ud. | ha comenzado |
| nosotros/as | hemos comenzado |
| vosotros/as | habéis comenzado |
| ellos/ellas/Uds. | han comenzado |
The present perfect connects the past with the present: something that has happened, often today or recently. It is haber in the present plus the past participle: «Hoy yo he comenzado». In Spain it is used for anything that happened today; in Latin America the preterite is often preferred.
Pluperfect
| Person | Form |
|---|---|
| yo | había comenzado |
| tú | habías comenzado |
| él/ella/Ud. | había comenzado |
| nosotros/as | habíamos comenzado |
| vosotros/as | habíais comenzado |
| ellos/ellas/Uds. | habían comenzado |
The pluperfect describes an event that happened before another past event: «Cuando llegué, ya había comenzado». It is haber in the imperfect plus the past participle, and it is the tense for explaining what had already happened when something else took place.
Future Perfect
| Person | Form |
|---|---|
| yo | habré comenzado |
| tú | habrás comenzado |
| él/ella/Ud. | habrá comenzado |
| nosotros/as | habremos comenzado |
| vosotros/as | habréis comenzado |
| ellos/ellas/Uds. | habrán comenzado |
The future perfect looks back from a future point: by then, something will already have happened. «Para mañana, yo habré comenzado» is the pattern — haber in the future plus the past participle. It is less common in speech but regular in formal writing.
Conditional Perfect
| Person | Form |
|---|---|
| yo | habría comenzado |
| tú | habrías comenzado |
| él/ella/Ud. | habría comenzado |
| nosotros/as | habríamos comenzado |
| vosotros/as | habríais comenzado |
| ellos/ellas/Uds. | habrían comenzado |
The conditional perfect expresses what would have happened: «Yo habría comenzado si hubiera podido». It is haber in the conditional plus the past participle, and it is the tense for regrets and missed chances.
Present Subjunctive
| Person | Form |
|---|---|
| yo | comience |
| tú | comiences |
| él/ella/Ud. | comience |
| nosotros/as | comencemos |
| vosotros/as | comencéis |
| ellos/ellas/Uds. | comiencen |
The present subjunctive appears after wishes, doubts, emotions and impersonal expressions: «Espero que él comience». The trigger is in the main clause; the subjunctive is the mood of uncertainty, desire and influence. Learn the yo form first — most of the table follows from it. This is one of the tenses where comenzar does not follow the regular -ar pattern, so learn the forms in the table above rather than guessing them from the infinitive.
Imperfect Subjunctive (-ra forms)
| Person | Form |
|---|---|
| yo | comenzara |
| tú | comenzaras |
| él/ella/Ud. | comenzara |
| nosotros/as | comenzáramos |
| vosotros/as | comenzarais |
| ellos/ellas/Uds. | comenzaran |
The imperfect subjunctive is the past partner of the present subjunctive, used after past-tense triggers and in si-clauses: «Si él comenzara, todo sería distinto». The table above shows the -ra forms, the ones you will hear most often. There is also a less common -se set built on the same stem.
Imperative — Affirmative
| Person | Form |
|---|---|
| tú | comienza |
| él/ella/Ud. | comience |
| nosotros/as | comencemos |
| vosotros/as | comenzad |
| ellos/ellas/Uds. | comiencen |
There is no yo form in the imperative — you cannot command yourself.
The affirmative imperative gives direct commands and instructions: «¡Comienza!». There is no yo form — you cannot command yourself. The tú form is the one you will use with friends and family, and the usted form with people you address formally. This is one of the tenses where comenzar does not follow the regular -ar pattern, so learn the forms in the table above rather than guessing them from the infinitive.
Imperative — Negative
| Person | Form |
|---|---|
| tú | comiences |
| él/ella/Ud. | comience |
| nosotros/as | comencemos |
| vosotros/as | comencéis |
| ellos/ellas/Uds. | comiencen |
There is no yo form in the imperative — you cannot command yourself.
The negative imperative tells someone not to do something: «¡No comiences!». Unlike the affirmative imperative, the negative forms come from the present subjunctive, which is why they look different. Never use the affirmative form after no. This is one of the tenses where comenzar does not follow the regular -ar pattern, so learn the forms in the table above rather than guessing them from the infinitive.
Example sentences
- Yo comienzo a estudiar todos los días. — I begin to study every day.
- Mi hermana comienza a estudiar mucho. — My sister begins to study a lot.
- Ayer yo comencé a estudiar por la tarde. — Yesterday I began to study in the afternoon.
- De pequeño, yo comenzaba a estudiar muchas veces. — As a child, I used to begin to study often.
- Mañana yo comenzaré a estudiar sin falta. — Tomorrow I will begin to study without fail.
- Si tuviera más tiempo, yo comenzaría a estudiar ahora mismo. — If I had more time, I would begin to study right now.
- Hoy yo he comenzado el lunes dos veces. — Today I have begun on Monday twice.
- Espero que él comience a estudiar pronto. — I hope he begins to study soon.
- ¡Comienza a estudiar ahora mismo! — Begin to study right now!
- Ahora mismo estoy comenzando a estudiar. — Right now I am beginning to study.
Common mistakes
1. Using the regular stem in the preterite
Wrong: comenzé
Right: comencé
Comenzar does not keep its infinitive stem here. The correct form is comencé; the regular-looking comenzé is a form learners invent by applying the standard endings to the wrong stem.
2. Using the imperfect for a finished event
Wrong: Ayer yo comenzaba a estudiar.
Right: Ayer yo comencé a estudiar.
Yesterday's finished action needs the preterite, comencé. The imperfect comenzaba describes what used to happen or what was going on, not a single completed event.
3. Confusing it with a similar verb
Wrong: *Comienzo estudiar.
Right: Comienzo a estudiar.
Comenzar is followed by a + infinitive: comienzo a estudiar, comienzo a trabajar.
4. Using the indicative after a subjunctive trigger
Wrong: Espero que tú comienzas a estudiar.
Right: Espero que tú comiences a estudiar.
After espero que, Spanish requires the subjunctive: comiences, not the indicative comienzas. Wishes, hopes and doubts all trigger this change.
5. Using the affirmative imperative after no
Wrong: No comienza a estudiar.
Right: No comiences a estudiar.
Negative commands use the subjunctive-based forms: no comiences. The affirmative comienza can never follow no.
Quiz
Test yourself on the forms above. Choose the correct answer, then check the key below.
1. What is the yo form of comenzar in the present tense?
- (a) comenzamos
- (b) comienza
- (c) comienzas
- (d) comienzo
2. What is the él/ella form of comenzar in the preterite?
- (a) comencé
- (b) comenzamos
- (c) comenzaste
- (d) comenzó
3. What is the nosotros form of comenzar in the imperfect?
- (a) comenzaba
- (b) comenzabas
- (c) comenzábamos
4. What is the tú form of comenzar in the future tense?
- (a) comenzaremos
- (b) comenzará
- (c) comenzarás
- (d) comenzaré
5. What is the ellos form of comenzar in the conditional?
- (a) comenzaría
- (b) comenzarían
- (c) comenzarías
6. What is the yo form of comenzar in the present perfect?
- (a) ha comenzado
- (b) has comenzado
- (c) he comenzado
- (d) hemos comenzado
7. After «Espero que…», what is the tú form of comenzar?
- (a) comencemos
- (b) comience
- (c) comiences
8. What is the nosotros form of comenzar in the imperfect subjunctive (-ra)?
- (a) comenzara
- (b) comenzáramos
- (c) comenzaras
9. What is the gerund of comenzar?
- (a) comenzado
- (b) comenzando
- (c) comenzar
- (d) comienzo
10. What is the past participle of comenzar?
- (a) comencé
- (b) comenzado
- (c) comenzando
- (d) comenzar
Answer key
1. (d) comienzo — In the present, the yo form of comenzar is comienzo. The other options are the same tense but different persons.
2. (d) comenzó — In the preterite, the el form of comenzar is comenzó. The other options are the same tense but different persons.
3. (c) comenzábamos — In the imperfect, the nosotros form of comenzar is comenzábamos. The other options are the same tense but different persons.
4. (c) comenzarás — In the future, the tu form of comenzar is comenzarás. The other options are the same tense but different persons.
5. (b) comenzarían — In the conditional, the ellos form of comenzar is comenzarían. The other options are the same tense but different persons.
6. (c) he comenzado — In the present perfect, the yo form of comenzar is he comenzado. The other options are the same tense but different persons.
7. (c) comiences — In the present subjunctive, the tu form of comenzar is comiences. The other options are the same tense but different persons.
8. (b) comenzáramos — In the imperfect subjunctive, the nosotros form of comenzar is comenzáramos. The other options are the same tense but different persons.
9. (b) comenzando — The gerund of comenzar is comenzando. It is used with estar for the progressive: «Estoy comenzando».
10. (b) comenzado — The past participle of comenzar is comenzado. It follows haber in all the perfect tenses: «he comenzado».
Frequently asked questions
Is comenzar regular or irregular?
No — comenzar is a stem-changing verb (e → ie). The stem vowel changes in the present tense, the present subjunctive and the imperative, and the tenses affected are: present, present-subjunctive, imperative-affirmative, imperative-negative. The nosotros and vosotros forms keep the original stem.
What are the gerund and past participle of comenzar?
The gerund is comenzando and the past participle is comenzado. Use the gerund with estar for actions in progress («Estoy comenzando») and the participle with haber for the perfect tenses («he comenzado»).
What is the difference between comenzar and empezar?
Comenzar and empezar are often confused. Empezar is a near-synonym for beginning; comenzar is slightly more formal.
How do I say «I begin» in Spanish?
Say «Yo comienzo». That is the yo form of the present tense, the form you need for talking about yourself right now.
Which forms of comenzar change the stem?
The stem changes (e → ie) in the present tense, the present subjunctive and the imperative — everywhere except the nosotros and vosotros forms. The preterite, imperfect, future and conditional keep the infinitive stem, except where the verb has an extra preterite change.
Related links
- Practise this verb in one tense: comenzar-present-tense
- More examples and a quiz: comenzar-examples-and-quiz
- Browse all Spanish verbs: /spanish/
- Full list of irregular verbs: spanish-irregular-verbs
- Related verb: terminar
- Related verb: continuar
- Related verb: acabar
- Conjugate any verb: verb-conjugator
- Test yourself: verb-quiz