Ser is used to say the identity of a person or thing, their profession, their origin, the material of an object, the time and the qualities that are considered stable. It appears in schemes such as subject + ser + name, subject + ser + profession, subject + ser + de + place, object + ser + de + material, and es + hour. It also marks traits that define something in a general way, such as nationality, the makeup of a family, or the habitual character of someone. With ser, the idea is not something momentary, but what something or someone is by nature, origin or definition.

Basic uses of ser in everyday context

Usage	Explanation
Identity	Ser is used to say who someone is or what something is when you define it clearly.
Profession or role	Ser is used to talk about the job, occupation, or role someone has.
Origin	Ser is used to indicate where a person or thing comes from.
Material	Ser is used to say what something is made of.
Time	Ser is used to tell the exact time.
Permanent characteristic	Ser is used to describe a quality that appears stable or defining.

The present of ser changes a lot: soy, eres, es, somos, sois, son. It is used to talk about who someone is, what something is, and how a person is identified in the present. In sentences like yo soy Marta, tú eres médico or ellos son mis vecinos, the verb links the subject with a definition. When it appears with adjectives, it presents traits that are understood as proper and not as passing states, as in la casa es grande or mi hermana es amable. To compare with another past time, the descriptive value connects well with the Imperfecto and, for completed actions, with the Pretérito.

Subject	Infinitive	Conjugation
yo	ser
él	ser
ellos	ser
nosotros	ser
vosotros	ser
tú	ser

Irregular present tense of the verb ser

Subject	Infinitive	Conjugation
yo	ser	soy
tú	ser	eres
él	ser	es
nosotros	ser	somos
vosotros	ser	sois
ellos	ser	son

Scramble

To say identity, ser goes in front of a name, a pronoun, a nickname or a definition: soy Ana, eres mi profesor, es mi hermano. With professions and roles, the usual pattern is subject + ser + profession or function: soy enfermera, él es director, somos estudiantes. It is not used for a momentary occupation, but for the profession or role that identifies the person in that context. That is why it also serves to name family, social or institutional roles: es madre, son socios, soy responsable del grupo.

Subject	Infinitive	Conjugation
ellos	ser
él	ser
yo	ser
nosotros	ser
vosotros	ser
tú	ser

Highly irregular past tense of ser

Subject	Infinitive	Conjugation
yo	ser	fui
tú	ser	fuiste
él	ser	fue
nosotros	ser	fuimos
vosotros	ser	fuisteis
ellos	ser	fueron

Scramble

With origin, ser is followed by de: soy de México, son de Valencia. This structure presents the provenance of a person, a family or a thing. For materials, the scheme is object + ser + de + material: la mesa es de madera, el anillo es de plata, la botella es de vidrio. With the time, the fixed form is ser + la(s) + number: son las tres, es la una y cuarto. In this use, the verb does not describe a quality; it simply places the exact moment on the clock.

Subject	Infinitive	Conjugation
nosotros	ser
yo	ser
tú	ser
vosotros	ser
ellos	ser
él	ser

Descriptive imperfect tense of the verb ser

Subject	Infinitive	Conjugation
yo	ser	era
tú	ser	eras
él	ser	era
nosotros	ser	éramos
vosotros	ser	erais
ellos	ser	eran

Scramble

Ser is used with adjectives and nouns for qualities that are understood as durable, essential or definitional. Thus, mi padre es tranquilo, el café es amargo, la película es italiana and la puerta es azul present traits that identify the subject or the object. It also appears in definitions and classifications: un gato es un animal, Madrid es una ciudad grande. If a quality changes easily and describes the momentary state, another verb is preferred; with ser, the focus is on what something is in a characteristic way.

Subject	Infinitive	Conjugation
yo	ser
vosotros	ser
él	ser
tú	ser
ellos	ser
nosotros	ser

Irregular future with the root ser

Subject	Infinitive	Conjugation
yo	ser	seré
tú	ser	serás
él	ser	será
nosotros	ser	seremos
vosotros	ser	seréis
ellos	ser	serán

Scramble

In the preterite, ser has very irregular forms: fui, fuiste, fue, fuimos, fuisteis, fueron. It is used for closed events in the past and for complete states at an earlier moment: ayer fui profesor en ese colegio, la reunión fue breve, ellos fueron muy amables. It can also express a change of identity or situation seen as a finished fact: fue campeón en 2019. When the past is narrated as background, description or repetition, the Imperfecto enters; when it is presented as a complete event, fui and its other forms are used.

Subject	Infinitive	Conjugation
vosotros	ser
tú	ser
nosotros	ser
él	ser
ellos	ser
yo	ser

Hypothetical conditional of the verb ser

Subject	Infinitive	Conjugation
yo	ser	sería
tú	ser	serías
él	ser	sería
nosotros	ser	seríamos
vosotros	ser	seríais
ellos	ser	serían

Scramble

The imperfect of ser is era, eras, era, éramos, erais, eran. It serves to describe people, places and situations in the past without closing the action, as the backdrop of a story: de niño era muy tímido, la casa era pequeña, mis padres eran maestros. It also expresses habits or states repeated in that era: siempre era puntual, los veranos eran tranquilos. In front of the Pretérito, which marks a finished fact, the imperfect presents a feature maintained over time or a scene already in progress.

Subject	Infinitive	Conjugation
él	ser
vosotros	ser
ellos	ser
nosotros	ser
tú	ser
yo	ser

Present subjunctive of ser

Subject	Infinitive	Conjugation
yo	ser	sea
tú	ser	seas
él	ser	sea
nosotros	ser	seamos
vosotros	ser	seáis
ellos	ser	sean

Scramble

The future of ser uses the irregular root ser- and the regular endings: seré, serás, será, seremos, seréis, serán. It is used to talk about identity, state or value at a later moment: mañana seré el encargado, la fiesta será en casa de Ana, serán las ocho. It also appears to express a guess about the present or the future, especially in phrases like será su hermano or serán unos veinte invitados. The meaning remains tied to identity or description, but located after the moment of speech.

Subject	Infinitive	Conjugation
vosotros	ser
tú	ser
usted	ser
ustedes	ser
nosotros	ser

Affirmative imperative of ser

Subject	Infinitive	Conjugation
tú	ser	sé
usted	ser	sea
nosotros	ser	seamos
vosotros	ser	sed
ustedes	ser	sean

Scramble

The conditional of ser follows the same pattern as the future with conditional endings: sería, serías, sería, seríamos, seríais, serían. It is used for hypotheses, imaginary consequences and polite expressions. In a possible situation, you hear in phrases like sería mejor salir temprano or seríamos más tranquilos en otro lugar. To sound softer or more formal, it appears in requests and evaluations: sería un placer, sería posible cambiar la hora. When the sentence depends on a condition, sería presents the thought result, not a real fact.

Verb	Subject	Infinitive	Conjugation
gerundio	Gerundio	ser
participio	Participio	ser

Non-personal forms of ser

Subject	Infinitive	Conjugation
Participio	ser	sido
Gerundio	ser	siendo

Scramble

The present subjunctive of ser is sea, seas, sea, seamos, seáis, sean. It appears after verbs and expressions that show doubt, desire, emotion, judgment or recommendation: quiero que seas sincero, dudo que sea verdad, es importante que sean puntuales. It is also used after impersonal expressions like es necesario que, es posible que and conviene que. The usual scheme is verb or expression of influence + que + ser in subjunctive, because the information is not yet presented as certain or affirmed.

The affirmative imperative of ser has two forms: sé for tú and sed for vosotros. It is used to command, advise or ask for a concrete attitude: sé valiente, sé discreto, sed prudentes. In these commands, ser often acts as an instruction about behavior or identity: sé tú mismo, sed pacientes. The form sé coincides with a very short irregular form and does not carry the r of the infinitive; sed preserves a brief and clear form for the plural.

The non-personal forms of ser are sido and siendo. Sido is the participle and is used in compound tenses with haber: he sido, había sido, habrá sido. It also appears in the passive voice with haber sido + participle of another verb: ha sido elegido. Siendo is the gerund and is used for actions or states in progress: está siendo difícil, sigue siendo mi amigo, estoy siendo sincero. These forms do not change with the person and preserve the sense of identity, state or characteristic that distinguishes ser.