Ser Conjugation in Spanish
ser means “be” in English, and it is one of the first verbs Spanish learners meet — it sits at number 1 in VerbFlow’s frequency list. You use it for identity, origin and nationality, for professions, relationships and characteristics, and for time, dates and descriptions with de. Because it comes up in everyday conversation so often, learning its forms properly pays off from the very first week. This page gives you the complete conjugation of ser — every tense, every person, the gerund and the past participle — with notes, examples, common mistakes and a quiz. Here is the verb in a natural sentence: “Yo soy médico en Madrid todos los días.” — “I am a doctor in Madrid every day.”
Quick facts
- Infinitive: ser
- English: to be
- Verb type: Irregular
- Irregular in: present, preterite, imperfect, present-subjunctive, imperfect-subjunctive, imperative-affirmative, imperative-negative
- Gerund: siendo
- Past participle: sido
- Auxiliary: haber (all perfect tenses are formed with haber + the past participle)
Full conjugation tables
Every form below comes from VerbFlow’s verified conjugation tables for ser. Learn the present tense first, then the preterite and the imperfect, and add the remaining tenses one at a time.
Present indicative
| Person | Form |
|---|---|
| yo | soy |
| tú | eres |
| él/ella/Ud. | es |
| nosotros/as | somos |
| vosotros/as | sois |
| ellos/ellas/Uds. | son |
Preterite
| Person | Form |
|---|---|
| yo | fui |
| tú | fuiste |
| él/ella/Ud. | fue |
| nosotros/as | fuimos |
| vosotros/as | fuisteis |
| ellos/ellas/Uds. | fueron |
Imperfect
| Person | Form |
|---|---|
| yo | era |
| tú | eras |
| él/ella/Ud. | era |
| nosotros/as | éramos |
| vosotros/as | erais |
| ellos/ellas/Uds. | eran |
Future
| Person | Form |
|---|---|
| yo | seré |
| tú | serás |
| él/ella/Ud. | será |
| nosotros/as | seremos |
| vosotros/as | seréis |
| ellos/ellas/Uds. | serán |
Conditional
| Person | Form |
|---|---|
| yo | sería |
| tú | serías |
| él/ella/Ud. | sería |
| nosotros/as | seríamos |
| vosotros/as | seríais |
| ellos/ellas/Uds. | serían |
Present perfect
| Person | Form |
|---|---|
| yo | he sido |
| tú | has sido |
| él/ella/Ud. | ha sido |
| nosotros/as | hemos sido |
| vosotros/as | habéis sido |
| ellos/ellas/Uds. | han sido |
Pluperfect (past perfect)
| Person | Form |
|---|---|
| yo | había sido |
| tú | habías sido |
| él/ella/Ud. | había sido |
| nosotros/as | habíamos sido |
| vosotros/as | habíais sido |
| ellos/ellas/Uds. | habían sido |
Future perfect
| Person | Form |
|---|---|
| yo | habré sido |
| tú | habrás sido |
| él/ella/Ud. | habrá sido |
| nosotros/as | habremos sido |
| vosotros/as | habréis sido |
| ellos/ellas/Uds. | habrán sido |
Conditional perfect
| Person | Form |
|---|---|
| yo | habría sido |
| tú | habrías sido |
| él/ella/Ud. | habría sido |
| nosotros/as | habríamos sido |
| vosotros/as | habríais sido |
| ellos/ellas/Uds. | habrían sido |
Present subjunctive
| Person | Form |
|---|---|
| yo | sea |
| tú | seas |
| él/ella/Ud. | sea |
| nosotros/as | seamos |
| vosotros/as | seáis |
| ellos/ellas/Uds. | sean |
Imperfect subjunctive (-ra)
| Person | Form |
|---|---|
| yo | fuera |
| tú | fueras |
| él/ella/Ud. | fuera |
| nosotros/as | fuéramos |
| vosotros/as | fuerais |
| ellos/ellas/Uds. | fueran |
Imperative (affirmative)
| Person | Form |
|---|---|
| tú | sé |
| él/ella/Ud. | sea |
| nosotros/as | seamos |
| vosotros/as | sed |
| ellos/ellas/Uds. | sean |
Imperative (negative)
| Person | Form |
|---|---|
| tú | seas |
| él/ella/Ud. | sea |
| nosotros/as | seamos |
| vosotros/as | seáis |
| ellos/ellas/Uds. | sean |
Gerund and past participle
| Form | Spanish |
|---|---|
| Gerund | siendo |
| Past participle | sido |
When to use each tense
Present indicative
The present indicative is used for habits, facts and things happening now. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “Yo soy médico en Madrid todos los días.” — “I am a doctor in Madrid every day.”
Preterite
The preterite is used for completed actions in the past. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “Tú fuiste de España ayer.” — “You were from Spain yesterday.”
Imperfect
The imperfect is used for ongoing or habitual actions in the past, and background description. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “Él era muy interesante antes.” — “He used to be very interesting before.”
Future
The future is used for what will happen, predictions and probability. For example: “Yo seré médico en Madrid mañana.” — “I will be a doctor in Madrid tomorrow.”
Conditional
The conditional is used for what would happen, polite requests and hypothetical situations. For example: “Tú serías de España algún día.” — “You would be from Spain someday.”
Present perfect
The present perfect is used for recent past actions and life experience, formed with haber + the past participle. For example: “Él ha sido muy interesante esta semana.” — “He has been very interesting this week.”
Pluperfect (past perfect)
The pluperfect (past perfect) is used for an action completed before another past action. For example: “Yo había sido médico en Madrid antes de la fiesta.” — “I had been a doctor in Madrid before the party.”
Future perfect
The future perfect is used for what will have happened by a point in the future. For example: “Tú habrás sido de España para mañana.” — “You will have been from Spain by tomorrow.”
Conditional perfect
The conditional perfect is used for what would have happened in a different past. For example: “Él habría sido muy interesante ayer.” — “He would have been very interesting yesterday.”
Present subjunctive
The present subjunctive is used for wishes, doubts, emotions and opinions after que. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “Es importante que yo sea médico en Madrid.” — “It is important that i be a doctor in Madrid.”
Imperfect subjunctive (-ra)
The imperfect subjunctive (-ra) is used for the past subjunctive: wishes and hypotheticals about the past, and clauses after a past-tense trigger. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “Ojalá tú fueras de España.” — “I wish you were from Spain.”
Imperative (affirmative)
The imperative (affirmative) is used for direct commands and instructions. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “¡Sé muy interesante!” — “Be very interesting!”
Imperative (negative)
The imperative (negative) is used for prohibitions and negative commands. With ser this tense is irregular, so the forms do not follow the regular pattern — learn them as a set rather than guessing from the infinitive. For example: “No seas médico en Madrid.” — “Do not be a doctor in Madrid.”
Example sentences
Ten natural sentences with ser, covering different tenses and persons. Say each one aloud, then cover the Spanish and try to produce it from the English.
- “Yo soy médico en Madrid todos los días.” — “I am a doctor in Madrid every day.”
- “Tú fuiste de España ayer.” — “You were from Spain yesterday.”
- “Él era muy interesante antes.” — “He used to be very interesting before.”
- “Yo seré de España mañana.” — “I will be from Spain tomorrow.”
- “Tú serías médico en Madrid algún día.” — “You would be a doctor in Madrid someday.”
- “Él ha sido muy interesante esta semana.” — “He has been very interesting this week.”
- “Yo había sido médico en Madrid antes de la fiesta.” — “I had been a doctor in Madrid before the party.”
- “Tú habrás sido de España para mañana.” — “You will have been from Spain by tomorrow.”
- “Es importante que él sea muy interesante.” — “It is important that he be very interesting.”
- “¡Sé médico en Madrid!” — “Be a doctor in Madrid!”
Common mistakes
1. Using the infinitive instead of a conjugated form
✗ Wrong: “Yo ser médico en Madrid.”
✓ Right: “Yo soy médico en Madrid.”
The infinitive ser never takes a subject. After yo you need the conjugated present form soy.
2. Confusing ser with estar
✗ Wrong: “Yo estoy médico en Madrid.”
✓ Right: “Yo soy médico en Madrid.”
Ser is for identity and permanent traits; estar is for location and temporary states.
3. Using ser for a temporary state
✗ Wrong: “Yo soy en Madrid.”
✓ Right: “Yo estoy en Madrid.”
Location is always estar, never ser. Say estoy en Madrid, not soy en Madrid.
4. Dropping the written accent
✗ Wrong: “sere”
✓ Right: “seré”
The accent on seré is part of the spelling in the future. Without it the form looks like a different word, so always write the accent.
5. Using the indicative after a subjunctive trigger
✗ Wrong: “Ojalá tú eres médico en Madrid.”
✓ Right: “Ojalá tú seas médico en Madrid.”
After ojalá Spanish needs the subjunctive, so use seas here, not the indicative eres.
6. Using the preterite for a habitual past action
✗ Wrong: “Yo fui médico en Madrid antes.” (said of a repeated habit)
✓ Right: “Yo era médico en Madrid antes.”
The preterite fui describes one finished action. For something you did regularly in the past, use the imperfect era.
Quiz: test yourself
Ten questions on ser. Choose the right form, then check the answer key below.
What is the yo form of ser in the Present indicative?
- A) eres
- B) es
- C) somos
- D) soy
What is the él/ella/Ud. form of ser in the Preterite?
- A) fuiste
- B) fuimos
- C) fue
- D) fui
What is the nosotros/as form of ser in the Imperfect?
- A) erais
- B) éramos
- C) era
- D) eras
What is the tú form of ser in the Future?
- A) serás
- B) seré
- C) será
- D) seremos
What is the yo form of ser in the Conditional?
- A) serías
- B) seríamos
- C) seríais
- D) sería
What is the él/ella/Ud. form of ser in the Present subjunctive?
- A) seamos
- B) seáis
- C) sea
- D) seas
What is the yo form of ser in the Imperfect subjunctive (-ra)?
- A) fuerais
- B) fuera
- C) fueras
- D) fuéramos
What is the gerund of ser?
- A) habiendo
- B) siendo
- C) estando
What is the past participle of ser?
- A) sido
- B) estado
- C) habido
What does ser mean in English?
- A) to be
- B) to have
Answer key
- D) soy — the yo form of ser in the present indicative is soy. The other options (eres, es, somos) are the same tense for different persons.
- C) fue — the él/ella/Ud. form of ser in the preterite is fue. The other options (fui, fuiste, fuimos) are the same tense for different persons.
- B) éramos — the nosotros/as form of ser in the imperfect is éramos. The other options (era, eras, era) are the same tense for different persons.
- A) serás — the tú form of ser in the future is serás. The other options (seré, será, seremos) are the same tense for different persons.
- D) sería — the yo form of ser in the conditional is sería. The other options (serías, sería, seríamos) are the same tense for different persons.
- C) sea — the él/ella/Ud. form of ser in the present subjunctive is sea. The other options (sea, seas, seamos) are the same tense for different persons.
- B) fuera — the yo form of ser in the imperfect subjunctive (-ra) is fuera. The other options (fueras, fuera, fuéramos) are the same tense for different persons.
- B) siendo — the gerund of ser is siendo; it is used with estar for the progressive. The other options are the gerunds of neighbouring verbs.
- A) sido — the past participle of ser is sido; perfect tenses use haber + sido. The other options are the participles of neighbouring verbs.
- A) to be — ser means “to be” in English. The other options are the meanings of neighbouring verbs.
Frequently asked questions
What does ser mean in English?
ser means “to be”. You use it for identity, origin and nationality, for professions, relationships and characteristics, and for time, dates and descriptions with de. It is a core everyday verb, so its present-tense forms are worth learning first.
Is ser regular or irregular?
ser is irregular, and it is irregular in these tenses: present, preterite, imperfect, present-subjunctive, imperfect-subjunctive, imperative-affirmative, imperative-negative. The gerund is siendo and the past participle is sido.
What are the gerund and past participle of ser?
The gerund is siendo — use it with estar for actions in progress. The past participle is sido — use it with haber for the perfect tenses, as in he sido (I have been).
What is the difference between ser and estar?
Ser is for identity and permanent traits; estar is for location and temporary states. If you are unsure, check the full table for estar and compare the meanings in context.
How do I say “I am” in Spanish?
Say “Yo soy médico en Madrid.” — “I am a doctor in Madrid every day.” The yo form of the present is soy, and it is the form you will use most often.
Related pages
- ser in the preterite tense — the full table and uses for this verb in its most practised tense.
- ser examples and quiz — more example sentences and practice questions for this verb.
- Spanish verbs — the full hub of Spanish conjugation pages.
- Spanish irregular verbs — every common irregular Spanish verb, grouped by pattern.
- Estar conjugation — another everyday Spanish verb.
- Haber conjugation — another everyday Spanish verb.
- Present tense guide — how the present tense works for regular verbs.
- Preterite tense guide — how the preterite works, and when to choose it over the imperfect.
- Verb Conjugator — practise ser with the interactive tool.
- Verb Quiz — practise ser with the interactive tool.
- Ser Vs Estar Quiz — practise ser with the interactive tool.