Introduction
Unir means “to join, to unite”, and it is one of the verbs you will use again and again in Spanish. Unir means to join or to unite, and it covers joining two pieces, uniting people and joining a club: unir las piezas, unir a la familia. It is a regular -ir verb. Its reflexive partner unirse means to join a group yourself. This page shows unir 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: “Uno las piezas del puzzle.” — I join the puzzle pieces.
Unir in real example sentences
The twelve sentences below are grouped by how unir 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 unir in the present tense, which is how you will meet it most often: routines, facts, and things happening now.
“Uno las piezas del puzzle.” — I join the puzzle pieces.
“¿Unes a la familia en Navidad?” — Do you join the family at Christmas?
“Une dos cables con cinta.” — He/she joins two cables with tape.
“Nosotros unimos los puntos con una línea.” — We join the dots with a line.
Talking about the past
The present is not the only tense you need. These sentences show unir in the past, so you can talk about what already happened.
“Ayer, yo uní las piezas del puzzle.” — Yesterday, I joined the puzzle pieces. (preterite)
“Antes, él unía a la familia en Navidad.” — Before, he used to join the family at Christmas. (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 unir stays the same.
“Mañana, nosotros uniremos dos cables con cinta.” — Tomorrow, we will join two cables with tape. (future)
“¿Tú has unido los puntos con una línea?” — Have you joined the dots with a line? (present perfect)
More everyday uses
Four more present-tense sentences, covering the remaining persons, so you can see the whole table in action.
“Vosotros unís las piezas del puzzle.” — You join the puzzle pieces.
“Ellos unen a la familia en Navidad.” — They join the family at Christmas.
“Yo uno dos cables con cinta.” — I join two cables with tape.
“Mi padre une los puntos con una línea.” — My father joins the dots with a line.
Unir 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 unir appears naturally, without anyone stopping to think about conjugation.
A short dialogue
Marta: “¿Tú unes a la familia en Navidad?” — Do you join the family at Christmas?
Pedro: “Sí, yo uno las piezas del puzzle.” — Yes, I join the puzzle pieces.
Marta: “Nosotros unimos los puntos con una línea.” — We join the dots with a line.
Pedro: “Y ellos unen a la familia en Navidad.” — And they join the family at Christmas.
Marta: “Vosotros unís dos cables con cinta.” — You join two cables with tape.
Pedro: “Sí, y él une las piezas del puzzle.” — Yes, and he joins the puzzle pieces.
A short paragraph
Une las piezas del puzzle, y nosotros unimos los puntos con una línea. Yo uno a la familia en Navidad, y ellos unen dos cables con cinta. Unir is part of everyday life, because join, to unite is something people do in work, at home and with friends, in the present, the past and the future.
Common mistakes with unir
These are the errors learners actually make with unir. Each one shows the wrong version, the right version, and why the correction matters.
Wrong: “Yo une las piezas del puzzle.” Right: “Yo uno las piezas del puzzle.” Why: The person matters: une is the él/ella/Ud. form, while the yo form is uno. Using the third-person form with yo is one of the most common beginner errors.
Wrong: “Ayer yo uno a la familia en Navidad.” Right: “Ayer yo uní a la familia en Navidad.” Why: The present and the preterite are different tenses: uno is happening now, while uní is a finished action in the past. Use the preterite with ayer.
Wrong: “Treating unir and unirse as identical in every context.” Right: “Unir means to join, to unite, while unirse means to join a group yourself.” Why: They overlap, but each has uses the other does not: unir fits sentences such as Uno las piezas del puzzle, while unirse belongs in a different sentence. Check the meaning you want before choosing.
Wrong: “Yo soy unido a la familia en Navidad.” Right: “Yo he unido a la familia en Navidad.” Why: Spanish perfect tenses use haber, not ser: he unido, has unido, ha unido. Ser plus the participle makes a passive, not a perfect tense.
Wrong: “De niño, yo uní dos cables con cinta todos los días.” Right: “De niño, yo unía dos cables con cinta todos los días.” Why: For a repeated habit in the past, use the imperfect (unía), not the preterite. The preterite (uní) is for one finished action.
Quiz: unir in use
Ten questions on unir in real sentences. Choose the correct answer for each one, then check the answer key. Every answer is explained.
1. Complete the sentence: “Vosotros ______ las piezas del puzzle.” (You join the puzzle pieces.)
- (a) unís
- (b) uno
- (c) unes
Answer: unís — The vosotros/as form of unir in the present tense is unís.
2. Complete the sentence: “Ellos ______ a la familia en Navidad.” (They join the family at Christmas.)
- (a) unes
- (b) unen
- (c) uno
Answer: unen — The ellos/ellas/Uds. form of unir in the present tense is unen.
3. Complete the sentence (preterite): “Ayer yo ______ las piezas del puzzle.” (Yesterday I joined the puzzle pieces.)
- (a) uniste
- (b) unió
- (c) uní
Answer: uní — In the preterite, the yo form of unir is uní.
4. Complete the sentence (imperfect): “Antes, él ______ a la familia en Navidad.” (Before, he used to join the family at Christmas.)
- (a) unía
- (b) uno
- (c) unías
Answer: unía — In the imperfect, the él/ella/Ud. form of unir is unía.
5. Complete the sentence (future): “Mañana, nosotros ______ dos cables con cinta.” (Tomorrow we will join two cables with tape.)
- (a) unirás
- (b) uniremos
- (c) uniré
Answer: uniremos — In the future, the nosotros/as form of unir is uniremos.
6. What does unir mean in English?
- (a) to join, to unite
- (b) to transmit
- (c) to join a group yourself
Answer: to join, to unite — Unir means “to join, to unite”. The other options are the meanings of different verbs.
7. Which sentence is correct?
- (a) Yo une las piezas del puzzle.
- (b) Ellos une a la familia en Navidad.
- (c) Yo uno las piezas del puzzle.
Answer: Yo uno las piezas del puzzle. — “Yo uno las piezas del puzzle.” is correct. The other two sentences contain the mistakes explained in the section above.
8. How do you say “I join the puzzle pieces.” in Spanish?
- (a) Mi padre une los puntos con una línea.
- (b) Uno las piezas del puzzle.
- (c) Unen las piezas del puzzle.
Answer: Uno las piezas del puzzle. — “Uno las piezas del puzzle.” is the correct translation.
9. What is the nosotros form of unir in the present tense?
- (a) uno
- (b) unes
- (c) unimos
Answer: unimos — The nosotros form is unimos.
10. Which of these sentences is in the present tense?
- (a) Mañana, nosotros uniremos dos cables con cinta.
- (b) Uno las piezas del puzzle.
- (c) Ayer, yo uní las piezas del puzzle.
Answer: Uno las piezas del puzzle. — “Uno las piezas del puzzle.” is in the present tense. The other two are in the preterite and the future.
Frequently asked questions
How do you say 'I join the puzzle pieces' in Spanish?
Say 'Uno las piezas del puzzle'. For a routine, add a time expression: 'Uno las piezas del puzzle todos los días'.
How do you say 'He joins the family at Christmas' in Spanish?
Say 'Él une a la familia en Navidad'. The subject comes first, and the verb agrees with it: él takes une.
What is the difference between unir and unirse?
Unir means to join, to unite, while unirse means to join a group yourself. They are easy to confuse because they appear in similar situations, but they are not interchangeable: use unir when you mean to join, to unite, as in 'Uno las piezas del puzzle', and use unirse for to join a group yourself.
Related pages
- Full conjugation of unir — every tense of unir in one place.
- Unir 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 unir and other verbs.
- Conjugation practice — drill the forms of unir until they are automatic.