Ser conjugation in every tense, with when to use each form
Ser is one of the two Spanish verbs for “to be”, and one of the most irregular verbs in the language. You need it to say who you are, where you are from, what time it is and what something is like. Below: every tense in tables, notes on when to use each one, and the mistakes English speakers make with it.
The full table is also on the ser conjugation page, where you can type every form of ser from memory and see which ones you got wrong.
When to use ser
Use ser to say what someone or something is. That covers identity (Soy Marta), profession (Es médico), nationality and origin (Somos de Chile), material (La mesa es de madera) and ownership (El coche es de mi hermano).
Use ser to describe characteristics: Es alta, Son muy simpáticos, La casa es grande.
Use ser for time, dates and prices at the till: Son las cinco, Hoy es martes, ¿Cuánto es?
Use ser to say where and when an event takes place: La fiesta es en mi casa, “The party is at my house”. For the location of people and things, use estar.
Use estar for feelings, states and location: Estoy cansado, Está en Madrid. The choice between the two has its own page, ser vs estar.
Present
| Person | ser | English |
|---|---|---|
| yo | soy | I am |
| tú | eres | you are |
| vos | sos | you are |
| él, ella, usted | es | he, she is / you are |
| nosotros, nosotras | somos | we are |
| vosotros, vosotras | sois | you are (Spain) |
| ellos, ellas, ustedes | son | they are / you are |
Preterite
Use the preterite to sum up a finished event or period: Fue un viaje increíble, “It was an incredible trip”. The preterite of ser is identical to the preterite of ir, so fui can mean “I was” or “I went”.
| Person | ser | English |
|---|---|---|
| yo | fui | I was |
| tú, vos | fuiste | you were |
| él, ella, usted | fue | he, she was / you were |
| nosotros | fuimos | we were |
| vosotros | fuisteis | you were (Spain) |
| ellos, ustedes | fueron | they were / you were |
Fui and fue have no written accent, because they are one syllable.
Imperfect
Use the imperfect to describe people, places and times in the past, and for the time of day: Era alto y tenía barba, “He was tall and had a beard”. Eran las ocho, “It was eight o’clock”.
| Person | ser | English |
|---|---|---|
| yo | era | I was |
| tú, vos | eras | you were |
| él, ella, usted | era | he, she was / you were |
| nosotros | éramos | we were |
| vosotros | erais | you were (Spain) |
| ellos, ustedes | eran | they were / you were |
Ser is one of only three verbs with an irregular imperfect. The others are ir and ver.
Future and conditional
The future and conditional of ser are regular.
| Person | Future | Conditional |
|---|---|---|
| yo | seré | sería |
| tú, vos | serás | serías |
| él, ella, usted | será | sería |
| nosotros | seremos | seríamos |
| vosotros | seréis | seríais |
| ellos, ustedes | serán | serían |
Use será to guess about now: Será verdad, “It’s probably true”. Sería is common in polite suggestions: Sería mejor esperar, “It would be better to wait”.
Present subjunctive
Use it after expressions of wishes, doubts and feelings, and in commands with usted: Espero que sea fácil, “I hope it’s easy”.
| Person | ser |
|---|---|
| yo | sea |
| tú, vos | seas |
| él, ella, usted | sea |
| nosotros | seamos |
| vosotros | seáis |
| ellos, ustedes | sean |
Imperfect subjunctive
Use it in si clauses and after past wishes: Si yo fuera tú, “If I were you”. Both sets are correct. The -se forms are more common in Spain.
| Person | -ra form | -se form |
|---|---|---|
| yo | fuera | fuese |
| tú, vos | fueras | fueses |
| él, ella, usted | fuera | fuese |
| nosotros | fuéramos | fuésemos |
| vosotros | fuerais | fueseis |
| ellos, ustedes | fueran | fuesen |
These are also the imperfect subjunctive forms of ir.
Commands
| Form | Affirmative | Negative |
|---|---|---|
| tú | sé | no seas |
| usted | sea | no sea |
| vosotros | sed | no seáis |
| ustedes | sean | no sean |
Sé with an accent is also “I know”, from saber. Sé bueno is “Be good”. No seas tonto is “Don’t be silly”. See Spanish commands for the rest.
Compound tenses
The participle is sido and the gerund is siendo. Compound tenses use haber with sido.
| Tense | yo form | English |
|---|---|---|
| Present perfect | he sido | I have been |
| Pluperfect | había sido | I had been |
| Future perfect | habré sido | I will have been |
| Conditional perfect | habría sido | I would have been |
| Perfect subjunctive | haya sido | I have been (subjunctive) |
| Pluperfect subjunctive | hubiera sido | I had been (subjunctive) |
Siendo appears in phrases like siendo sincero, “to be honest”. Estar siendo is less common but correct: Está siendo un año difícil, “It’s turning out to be a difficult year”.
Two more patterns with ser
Es + adjective + infinitive. This is how you say “it is important to”, “it is hard to”, “it is better to”: Es importante llegar pronto, Es difícil aparcar aquí, Es mejor esperar. With a new subject, use que and the subjunctive: Es importante que llegues pronto, “It’s important that you arrive early”.
The passive. Use ser with a participle to form the passive: La catedral fue construida en el siglo XIII, “The cathedral was built in the 13th century”. The participle agrees with the subject. You will see the passive with ser mostly in writing and news. In speech, people use se: Se construyó en el siglo XIII.
Fixed phrases with ser
| You want to say | Spanish | Notes |
|---|---|---|
| I mean, that is | o sea | Very common filler in speech |
| That is to say | es decir | More formal than o sea |
| The thing is | es que | Introduces an excuse or explanation |
| What time is it? | ¿Qué hora es? | |
| How much is it? | ¿Cuánto es? | At the till |
| Once upon a time | Érase una vez | Fairy tales |
| Unless | a no ser que | Followed by the subjunctive |
| Anyway, however it is | sea como sea | |
| It’s me | Soy yo | Spanish does not say es yo |
Worked examples
- Soy de Irlanda. I’m from Ireland.
- ¿Eres estudiante? Are you a student?
- Sos muy amable. You’re very kind. (Argentina)
- Es la una y media. It’s half past one.
- Son las tres. It’s three o’clock.
- La reunión es a las diez en la sala dos. The meeting is at ten in room two.
- Mi abuela era profesora. My grandmother was a teacher.
- Fue un día muy largo. It was a very long day.
- Eran las once cuando llegamos. It was eleven when we arrived.
- Será mejor que nos vayamos. We’d better go.
- Quiero que seas feliz. I want you to be happy.
- Si fuera más barato, lo compraría. If it were cheaper, I would buy it.
Common mistakes English speakers make
| Wrong | Right | Why |
|---|---|---|
| Soy cansado. | Estoy cansado. | Use estar for a state. |
| Soy en Madrid. | Estoy en Madrid. | Use estar for where people are. |
| Soy 30 años. | Tengo 30 años. | Use tener for age. |
| Es las tres. | Son las tres. | Use son with plural hours. Only one o’clock is es la una. |
| Fueron las ocho. | Eran las ocho. | Use the imperfect for clock time in the past. |
| Si yo sería tú. | Si yo fuera tú. | After si, use the imperfect subjunctive. |
| Es yo. | Soy yo. | The verb agrees with yo. |
| Fué. | Fue. | Fue and fui never have a written accent. |
Regional notes
Vos sos. In Argentina, vos sos replaces tú eres: ¿Vos sos de acá?, “Are you from here?” You will also hear sos in parts of Colombia, such as Medellín, and in much of Central America. The other tenses of vos are the same as tú, except the present and the command.
Vosotros sois. Only in Spain do people use vosotros: ¿Sois de aquí? In Mexico, Colombia and Argentina the same question to a group of friends is ¿Son de aquí?
Fuera and fuese. In Spain people use both imperfect subjunctive sets in speech. In Mexico, Colombia and Argentina, people mostly use the -ra form.
Practise it
Ser is in two lessons of the Vozelu grammar course: “Ser and estar” and “Present tense verbs”. To take them, create an account. In the lessons you read the forms and when to use each verb, then you type them in full sentences and are told what you got wrong.
Questions people ask
What are the forms of ser in the present tense? Soy, eres, es, somos, sois, son. With vos, the form is sos.
What is the preterite of ser? Fui, fuiste, fue, fuimos, fuisteis, fueron. It is the same as the preterite of ir, so you tell “was” from “went” by the context.
When do I use era and when fue? Use era to describe how someone or something was, and for the time: Era simpático, Eran las dos. Use fue to sum up an event or period: Fue una fiesta genial.
Why is it “son las dos” and not “es las dos”? The verb agrees with the number of hours. One o’clock is singular, es la una. Every other hour is plural, son las dos.
Is ser used for location? For events, yes: El concierto es en el estadio. For people, places and objects, use estar: El estadio está en el centro.
What does “o sea” mean? It means “I mean” or “in other words”. It is very common in speech in every country.
Is ser irregular in every tense? No. The future and conditional are regular: seré, sería. Almost everything else is irregular.