Ser Conjugation: All Spanish Tenses

Ser (to be: identity, origin, profession, qualities) is the most used verb in Spanish and it is completely irregular: it combines different stems depending on the tense - soy, eres in the present, fui in the preterite, era in the imperfect and sea in the subjunctive. Only the future and the conditional are built regularly on the infinitive.

Indicative Tenses of Ser

Ser in the Present (Presente)

Identity, origin, profession and permanent traits: Soy arquitecta y mi hermano es músico (I am an architect and my brother is a musician).

Present tense rules →

Ser in the Preterite (Pretérito indefinido)

Completed facts and judgements about past events: El concierto fue inolvidable y los músicos fueron muy amables (The concert was unforgettable and the musicians were very kind).

Preterite rules →

Ser in the Present Perfect (Pretérito perfecto)

Past connected to the present: Este invierno ha sido el más frío en muchos años (This winter has been the coldest in many years).

Present perfect rules →

Ser in the Imperfect (Pretérito imperfecto)

Descriptions and habitual situations in the past: Mi abuela era maestra y su escuela era muy pequeña (My grandmother was a teacher and her school was very small).

Imperfect rules →

Ser in the Past Perfect (Pluscuamperfecto)

A situation before another past moment: Nunca había sido tan feliz como aquel verano (I had never been as happy as that summer).

Past perfect rules →

Ser in the Future (Futuro simple)

Predictions and promises: Estoy seguro de que serás un gran médico (I am sure you will be a great doctor).

Future tense rules →

Ser in the Future Perfect (Futuro perfecto)

Assumptions about the recent past: Imagino que el viaje habrá sido agotador (I imagine the trip must have been exhausting).

Future perfect rules →

Ser in the Conditional (Condicional simple)

Suggestions and hypothetical situations: Sería mejor empezar la reunión a las nueve (It would be better to start the meeting at nine).

Conditional rules →

Ser in the Conditional Perfect (Condicional compuesto)

Hypotheses about the past: Sin tu ayuda, el proyecto habría sido un desastre (Without your help, the project would have been a disaster).

Conditional perfect rules →

Subjunctive Tenses of Ser

Present Subjunctive of Ser (Presente de subjuntivo)

Wishes, advice and value judgements: Es importante que seas puntual en la entrevista (It is important that you are punctual at the interview).

Present subjunctive rules →

Present Perfect Subjunctive of Ser (Pretérito perfecto de subjuntivo)

Evaluating a recent past action: Me alegro de que la reunión haya sido útil (I am glad the meeting has been useful).

Perfect subjunctive rules →

Imperfect Subjunctive of Ser (Pretérito imperfecto de subjuntivo)

Hypothetical conditions: Si fuera rico, viajaría por todo el mundo (If I were rich, I would travel around the world).

Imperfect subjunctive rules →

Past Perfect Subjunctive of Ser (Pluscuamperfecto de subjuntivo)

Unreal hypotheses about the past: Si hubiera sido más valiente, habría aceptado el trabajo (If I had been braver, I would have accepted the job).

Past perfect subjunctive rules →

Imperative of Ser

Affirmative Commands of Ser (Imperativo afirmativo)

Orders and advice: ¡Sé amable con los invitados! (Be kind to the guests!)

Affirmative commands rules →

Negative Commands of Ser (Imperativo negativo)

Prohibitions and negative advice: No seas tan duro contigo mismo (Don't be so hard on yourself).

Negative commands rules →

Expressions with Ser

• Érase una vez - once upon a time (classic fairy-tale opening)
• Ser uña y carne - to be inseparable, as thick as thieves (literally: to be nail and flesh)
• Ser pan comido - to be a piece of cake, very easy (literally: to be eaten bread)
• No es para tanto - it's not that big a deal
• Llegar a ser - to become something over time and through effort