Spanish Verb Ser Conjugation

College students
Ellos son estudiantes en la universidad. (They are college students).

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The verb ser is one of the two Spanish verbs that mean "to be." The other one is the verb estar. The verb ser is irregular, meaning it does not follow a common conjugation pattern. In fact, ser is one of the most irregularly conjugated verbs in Spanish. Many of the conjugated forms don't even begin with s, and some forms are shared with the highly irregular verb ir (to go).

This article includes the ser conjugations in the present, past, conditional and future indicative, the present and past subjunctive, the imperative, and other verb forms.

Using the Verb Ser

Ser and estar are some of the most commonly used verbs in Spanish. Although they both mean "to be," they are used in very different contexts. Ser is often used to talk about inherent or permanent characteristics. For example, Ella es alta e inteligente (She is tall and smart). It is also used to talk about someone's profession or occupation, as in Ella es doctora y él es arquitecto (She is a doctor and he is an engineer), or to talk about where someone is from, as in El profesor es de Puerto Rico (The professor is from Puerto Rico).

Ser can be used to talk about what something is made of, as in La puerta es de madera (The door is made of wood), or to talk about the location of an event, such as a meeting, party, festival, etc. For example, La reunión es en la oficina del doctor (The meeting is in the doctor's office).

This verb is also used to talk about belonging. For example, La casa es de Alberto (The house is Alberto's). Another use of the verb ser is in the passive voice, followed by the present participle, as in La tarea es hecha por el estudiante (The homework is done by the student).

Yet another use of the verb ser is with impersonal expressions, such as Es necesario trabajar duro (It is necessary to work hard).

Notice that in Spanish we do not use the verb ser to talk about someone's age like we do in English (She is ten years old), but instead we use the verb tener to talk about how many years someone has (Ella tiene diez años).

Ser Present Indicative

The conjugations for ser in the present indicative tense are totally irregular. The first person singular conjugation soy is similar to other verbs like dar (doy), estar (estoy) and ir (voy).

Yo soy I am Yo soy estudiante en la universidad.
eres You are Tú eres muy lista.
Usted/él/ella es You/he/she is Ella es doctora.
Nosotros somos We are Nosotros somos buenos amigos.
Vosotros sois You are Vosotros sois muy delgados.
Ustedes/ellos/ellas son You/they are Ellos son personas trabajadoras.

Ser Preterite Indicative

The preterite tense conjugations of ser are also irregular, since they do not resemble the infinitive ser at all. Note that these conjugations are the exact same conjugations for the preterite indicative tense of the verb ir (to go). From context, you would be able to tell if you are talking about being or going.

Yo fui I was Yo fui estudiante en la universidad.
fuiste You were Tú fuiste muy lista.
Usted/él/ella fue You/he/she was Ella fue doctora.
Nosotros fuimos We were Nosotros fuimos buenos amigos.
Vosotros fuisteis You were Vosotros fuisteis muy delgados.
Ustedes/ellos/ellas fueron You/they were Ellos fueron personas trabajadoras.

Ser Imperfect Indicative

Ser is one of the few verbs that are irregular in the imperfect tense, since it does not use either of the usual imperfect conjugation endings (ía or aba). Remember that the imperfect tense can be translated as "was being" or "used to be."

Yo era I used to be Yo era estudiante en la universidad.
eras You used to be Tú eras muy lista.
Usted/él/ella era You/he/she used to be Ella era doctora.
Nosotros éramos We used to be Nosotros éramos buenos amigos.
Vosotros erais You used to be Vosotros erais muy delgados.
Ustedes/ellos/ellas eran You/they used to be Ellos eran personas trabajadoras.

Ser Future Indicative

The future indicative tense is conjugated regularly, since you can start with the infinitive (ser) and add the future tense endings (é, ás, á, emos, áis, án).

Yo seré I will be Yo seré estudiante en la universidad.
serás You will be Tú serás muy lista.
Usted/él/ella será You/he/she will be Ella será doctora.
Nosotros seremos We will be Nosotros seremos buenos amigos.
Vosotros seréis You will be Vosotros seréis muy delgados.
Ustedes/ellos/ellas serán You/they will be Ellos serán personas trabajadoras.

Ser Periphrastic Future Indicative 

The periphrastic future is formed with three components: the present indicative conjugation of the verb ir (to go), the preposition a, and the infinitive ser.

Yo voy a ser I am going to be Yo voy a ser estudiante en la universidad.
vas a ser You are going to be Tú vas a ser muy lista.
Usted/él/ella va a ser You/he/she are going to be Ella va a ser doctora.
Nosotros vamos a ser We are going to be Nosotros vamos a ser buenos amigos.
Vosotros vais a ser You are going to be Vosotros vais a ser muy delgados.
Ustedes/ellos/ellas van a ser You/they are going to be Ellos van a ser personas trabajadoras.

Ser Present Progressive/Gerund Form

The gerund or present participle is formed with the stem of the verb and the ending -iendo (for -er and -ir verbs). It can be used to form progressive tenses like the present progressive, which is usually accompanied by the auxiliary verb estar.

Present Progressive of Ser está siendo She is being Ella está siendo una buena doctora al cuidar de sus pacientes.

Ser Past Participle

The past participle is used to form perfect tenses like the present perfect, which is formed with the auxiliary verb haber and the past participle sido.

Present Perfect of Ser ha sido She has been Ella ha sido doctora durante toda su carrera.

Ser Conditional Indicative

The conditional tense is normally translated to English as "would + verb." It is formed regularly like the future tense, by starting with the infinitive form and adding the conditional endings.

Yo sería I will be Yo sería estudiante en la universidad si me hubieran admitido.
serías You will be Tú serías muy lista si estudiaras más.
Usted/él/ella sería You/he/she will be Ella sería doctora si no hubiera estudiado leyes.
Nosotros seríamos We will be Nosotros seríamos buenos amigos si viviéramos más cerca.
Vosotros seríais You will be Vosotros seríais muy delgados si hicierais dieta.
Ustedes/ellos/ellas serían You/they will be Ellos serían personas trabajadoras si quisieran.

Ser Present Subjunctive

The conjugation of the present subjunctive of ser is completely irregular.

Que yo sea That I be  Mi madre quiere que yo sea estudiante en la universidad.
Que tú seas That you be A la maestra le encanta que tú seas muy lista.
Que usted/él/ella sea That you/he/she be Papá espera que ella sea doctora.
Que nosotros seamos That we be El consejero quiere que nosotros seamos buenos amigos.
Que vosotros seáis That you be El médico recomienda que vosotros seáis muy delgados.
Que ustedes/ellos/ellas sean That you/they be El jefe espera que ellos sean personas trabajadoras.

Ser Imperfect Subjunctive

You can conjugate the imperfect subjunctive in two different ways, both considered correct.

Option 1

Que yo fuera That I were Mamá quería que yo fuera estudiante en la universidad.
Que tú fueras That you were A la maestra le encantaba que tú fueras muy lista.
Que usted/él/ella fuera that you/he/she were Papá esperaba que ella fuera doctora.
Que nosotros fuéramos That we were El consejero quería que nosotros fuéramos buenos amigos.
Que vosotros fuerais That you were El médico recomendaba que vosotros fuerais muy delgados.
Que ustedes/ellos/ellas fueran That you/they were El jefe esperaba que ellos fueran personas trabajadoras.

Option 2

Que yo fuese That I were Mamá quería que yo fuese estudiante en la universidad.
Que tú fueses That you were A la maestra le encantaba que tú fueses muy lista.
Que usted/él/ella fuese that you/he/she were Papá esperaba que ella fuese doctora.
Que nosotros fuésemos That we were El consejero quería que nosotros fuésemos buenos amigos.
Que vosotros fueseis That you were El médico recomendaba que vosotros fueseis muy delgados.
Que ustedes/ellos/ellas fuesen That you/they were El jefe esperaba que ellos fuesen personas trabajadoras.

Ser Imperative

The imperative mood is used to give commands or orders. The tables below show both positive and negative commands.

Positive commands

Be! ¡Sé muy lista!
Usted sea Be! ¡Sea doctora!
Nosotros seamos Let's be! ¡Seamos buenos amigos!
Vosotros sed Be! ¡Sed muy delgados!
Ustedes sean Be! ¡Sean personas trabajadoras!

Negative commands

no seas Don't be! ¡No seas muy lista!
Usted no sea Don't be! ¡No sea doctora!
Nosotros no seamos Let's not be! ¡No seamos buenos amigos!
Vosotros no seáis Don't be! ¡No seáis muy delgados!
Ustedes no sean Don't be! ¡No sean personas trabajadoras!
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Your Citation
Erichsen, Gerald. "Spanish Verb Ser Conjugation." ThoughtCo, Feb. 14, 2021, Erichsen, Gerald. (2021, February 14). Spanish Verb Ser Conjugation. Retrieved from Erichsen, Gerald. "Spanish Verb Ser Conjugation." ThoughtCo. (accessed March 27, 2023).