Subjunctive of Ser

Ser is one of the small group of verbs whose present subjunctive cannot be derived from the yo form of the indicative. Its subjunctive stem is se-, which you simply have to memorize. The good news is that once you have the stem, the endings are the same regular -a endings used for every non--ar verb.

Conjugation

SubjectPresent Subjunctive
yosea
túseas
él / ella / ustedsea
nosotrosseamos
ellos / ellas / ustedessean

Notice the pattern: a two-letter stem se- plus the usual endings. All five forms are short, and none of them carries a written accent.

Why It's Irregular

The present indicative of ser (soy, eres, es, somos, son) gives no obvious starting point for the subjunctive. If we tried to start from soy and drop the -o, we'd get nothing. So instead, ser preserves an archaic stem from Latin and builds its subjunctive on se-.

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Memory cue: every form of the subjunctive of ser looks like the infinitive se-r with the r replaced by a regular ending. That mental image (se + a) makes the table much easier to recall.

Examples

Because ser is used to describe identity, profession, nationality, time, and intrinsic qualities, its subjunctive shows up very often in sentences that express wishes or judgments about what something is.

Espero que seas muy feliz en tu nuevo trabajo.

I hope you are very happy in your new job.

Es necesario que seamos puntuales mañana.

It's necessary that we be on time tomorrow.

Ojalá que la película sea interesante.

I hope the movie is interesting.

No creo que ellos sean hermanos.

I don't think they are siblings.

Mis padres quieren que yo sea médico.

My parents want me to be a doctor.

Es importante que sean honestos con nosotros.

It's important that they be honest with us.

Common Fixed Expressions

A few set phrases with ser in the subjunctive are worth memorizing as chunks:

  • sea como sea — "whatever happens" / "come what may"
  • sea lo que sea — "whatever it may be"
  • o sea — "in other words" / "that is to say"

Sea como sea, tenemos que terminar el proyecto hoy.

Come what may, we have to finish the project today.

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Don't confuse sea (subjunctive) with sea as a noun. In subjunctive usage, sea always appears in a dependent clause or a formulaic expression, never as a standalone noun.

Ser vs. Estar in the Subjunctive

As in the indicative, ser and estar are not interchangeable. Ser is used for qualities viewed as defining or permanent; estar is used for states, locations, and temporary conditions. In the subjunctive, that distinction is unchanged.

Ser (subjunctive)Estar (subjunctive)
seaesté
seasestés
seaesté
seamosestemos
seanestén

Compare these two sentences side by side:

Quiero que seas amable con todos.

I want you to be kind to everyone.

Here ser describes a personality trait.

Quiero que estés tranquilo cuando lleguemos.

I want you to be calm when we arrive.

Here estar describes a temporary state.

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When in doubt, ask yourself: is the quality describing what or who something is? Use ser. Is it describing how something feels or where it is right now? Use estar.

Next, look at the matching table for estar, which is also irregular but in a different way.

Related Topics

  • Subjunctive of EstarB1 — Estar's present subjunctive carries written accents on almost every form: esté, estés, esté, estemos, estén.
  • Subjunctive of IrB1 — Ir has a completely irregular present subjunctive built on the stem vay-.
  • Subjunctive Triggers OverviewB1 — An overview of the WEIRDO categories that introduce the subjunctive in Spanish dependent clauses.