Introduction
Comenzar means “to begin, to start”, and it is one of the verbs you will use every day in Spanish. Comenzar is the verb for beginning something: a class, a book, a job. The thing begun is the direct object, with no preposition. Comenzar a + infinitive means to begin to do something. The a is part of the structure, and it appears whenever an infinitive follows. This page shows comenzar in real sentences, in short dialogues, and in the mistakes learners make most often, and it finishes with a ten-question quiz so you can test yourself. Every sentence below comes with its English translation, and every form is the correct present-tense form unless the sentence is clearly marked as past or future. For a first taste: “Yo comienzo un libro nuevo.” — I begin a new book.
Comenzar in real example sentences
The twelve sentences below are grouped by how comenzar is used. Read each one out loud, then read the translation. If a sentence feels useful, copy it into your own notebook with one small change — a different time, a different person, a different place — and you have a new sentence of your own.
In the present: everyday use
These sentences use comenzar in the present tense, which is how you will meet it most often: routines, facts, and things happening now.
“Yo comienzo un libro nuevo.” — I begin a new book.
“¿Tú comienzas a estudiar?” — Are you beginning to study?
“La clase comienza a las nueve.” — The class begins at nine.
“Nosotros comenzamos el curso en septiembre.” — We begin the course in September.
Talking about the past
The present is not the only tense you need. These sentences show comenzar in the past, so you can talk about what already happened.
“Ayer yo comencé un libro nuevo.” — Yesterday I began a new book. (preterite)
“La clase comenzaba a las nueve siempre.” — The class always used to begin at nine. (imperfect)
Plans and things already done
These sentences look forward, or look back at something already finished. Notice how the verb form changes while the meaning of comenzar stays the same.
“Nosotros comenzaremos el curso en septiembre.” — We will begin the course in September. (future)
“¿Tú has comenzado ya a estudiar?” — Have you begun to study yet? (present perfect)
More everyday uses
Four more present-tense sentences, covering the remaining persons, so you can see the whole table in action.
“Vosotros comenzáis a trabajar.” — You begin to work.
“Ellos comienzan la reunión.” — They begin the meeting.
“Yo comienzo a cocinar.” — I begin to cook.
“El concierto comienza a las ocho.” — The concert begins at eight.
Comenzar in context
Single sentences teach you the forms. Dialogues teach you when to use them. Read the short conversation below, then the paragraph that follows, and notice how comenzar appears naturally, without anyone stopping to think about conjugation.
A short dialogue
Ana: “¿Tú comienzas a estudiar?” — Are you beginning to study?
Luis: “Sí, yo comienzo un libro nuevo.” — Yes, I begin a new book.
Ana: “Nosotros comenzamos el curso en septiembre.” — We begin the course in September.
Luis: “Y ellos comienzan la reunión.” — And they begin the meeting.
Ana: “Vosotros comenzáis a trabajar.” — You begin to work.
Luis: “Sí, y la clase comienza a las nueve.” — Yes, and the class begins at nine.
A short paragraph
Ana comienza un libro nuevo, y la clase comienza a las nueve. Nosotros comenzamos el curso en septiembre, y ellos comienzan la reunión. Yo comienzo a cocinar, y el concierto comienza a las ocho. Comenzar is part of every beginning, because beginning a book, beginning to study and beginning at nine are all part of the same verb.
Common mistakes with comenzar
These are the errors learners actually make with comenzar. Each one shows the wrong version, the right version, and why the correction matters.
Wrong: “Yo comenzamos un libro nuevo.” Right: “Yo comienzo un libro nuevo.” Why: The yo form is comienzo, with the e → ie change, not comenzamos. The change appears in yo, tú, él and ellos, while nosotros and vosotros keep the e: comenzamos, comenzáis.
Wrong: “Nosotros comienzan el curso.” Right: “Nosotros comenzamos el curso.” Why: Nosotros keeps the unchanged stem: comenzamos, not comienzan. The stem change never applies to nosotros or vosotros.
Wrong: “Yo comienzo estudiar.” Right: “Yo comienzo a estudiar.” Why: Comenzar + infinitive needs the preposition a: comienzo a estudiar, not comienzo estudiar. Dropping the a is a direct transfer from English, where 'begin to study' keeps the to, but Spanish needs its own a.
Wrong: “Ellos comienza la reunión.” Right: “Ellos comienzan la reunión.” Why: Ellos needs the ellos form comienzan. The singular comienza belongs with él, ella or a singular noun such as la clase.
Wrong: “Ellos comienzo todos los días.” Right: “Ellos comienzan todos los días.” Why: The verb must agree with its subject. Ellos needs the ellos form comienzan, not the yo form comienzo. This is the most common agreement slip in the present tense, and it happens because learners memorise the yo form first and then reuse it for every person.
Quiz: comenzar in use
Ten questions on comenzar in real sentences. Choose the correct answer for each one, then check the answer key. Every answer is explained.
1. Complete the sentence: “Vosotros ______ a trabajar.” (You begin to work.)
- (a) comienzas
- (b) comenzáis
- (c) comienzo
Answer: comenzáis — The vosotros/as form of comenzar in the present tense is comenzáis.
2. Complete the sentence: “Ellos ______ la reunión.” (They begin the meeting.)
- (a) comienzan
- (b) comienzo
- (c) comienzas
Answer: comienzan — The ellos/ellas/Uds. form of comenzar in the present tense is comienzan.
3. Complete the sentence (preterite): “Ayer yo ______ un libro nuevo.” (Yesterday I began a new book.)
- (a) comenzaste
- (b) comenzó
- (c) comencé
Answer: comencé — In the preterite, the yo form of comenzar is comencé.
4. Complete the sentence (imperfect): “La clase ______ a las nueve siempre.” (The class always used to begin at nine.)
- (a) comenzabas
- (b) comenzaba
- (c) comenzaba
Answer: comenzaba — In the imperfect, the él/ella/Ud. form of comenzar is comenzaba.
5. Complete the sentence (future): “Nosotros ______ el curso en septiembre.” (We will begin the course in September.)
- (a) comenzaremos
- (b) comenzaré
- (c) comenzarás
Answer: comenzaremos — In the future, the nosotros/as form of comenzar is comenzaremos.
6. What does comenzar mean in English?
- (a) to finish, to end
- (b) to serve
- (c) to begin, to start
Answer: to begin, to start — Comenzar means “to begin, to start”. The other options are the meanings of different verbs.
7. Which sentence is correct?
- (a) Yo comienzo un libro nuevo.
- (b) Yo comenzamos un libro nuevo.
- (c) Nosotros comienzan el curso.
Answer: Yo comienzo un libro nuevo. — “Yo comienzo un libro nuevo.” is correct. The other two sentences contain the mistakes explained in the section above.
8. How do you say “I begin to cook.” in Spanish?
- (a) Yo comienzan a cocinar.
- (b) Yo comienzo a cocinar.
- (c) El concierto comienza a las ocho.
Answer: Yo comienzo a cocinar. — “Yo comienzo a cocinar.” is the correct translation. The second option means something different, and the third uses the wrong person's form.
9. What is the nosotros form of comenzar in the present tense?
- (a) comienzo
- (b) comienzas
- (c) comenzamos
Answer: comenzamos — The nosotros form is comenzamos.
10. Which of these sentences is in the present tense?
- (a) Ayer yo comencé un libro nuevo.
- (b) Nosotros comenzaremos el curso en septiembre.
- (c) Yo comienzo un libro nuevo.
Answer: Yo comienzo un libro nuevo. — “Yo comienzo un libro nuevo.” is in the present tense. The other two are in the preterite and the future.
Frequently asked questions
How do you say 'I begin a new book' in Spanish?
Say 'Comienzo un libro nuevo'. The book follows directly with no preposition. For a routine: 'Comienzo un libro nuevo cada mes'.
How do you say 'The class begins at nine' in Spanish?
Say 'La clase comienza a las nueve'. The class is the subject, and the time takes the preposition a.
What is the difference between comenzar and empezar?
The two are synonyms, and both mean to begin or to start. Empezar is slightly more common in everyday speech, while comenzar is slightly more formal. In most sentences they are interchangeable.
Related pages
- Full conjugation of comenzar — every tense of comenzar in one place.
- Comenzar in the present tense — the full table and usage rules for one tense.
- Spanish verbs — the hub for every Spanish verb on VerbFlow.
- Verb quiz — test yourself on comenzar and other verbs.
- Conjugation practice — drill the forms of comenzar until they are automatic.