Section 18.3 · ser → sea/sean · ir → vaya/vayan · saber → sepa/sepan · dar → dé/den · estar → esté/estén · memorized forms, cannot be built from yo · accent on dé and esté
📖 Introduction — Section 18.3: The Five Exceptions
Sections 18.1 and 18.2 established the vowel swap rule: build any formal command by starting from the yo form, dropping -o, and adding the opposite vowel. That rule works for the vast majority of Spanish verbs — including those with irregular yo forms like hago, tengo, digo, pongo, vengo. Section 18.3 covers the five verbs that are exceptions to this rule entirely.
These five verbs — ser, ir, saber, dar, and estar — have formal command forms that cannot be derived from any present-tense yo form. They must be memorized as fixed forms: sea/sean · vaya/vayan · sepa/sepan · dé/den · esté/estén. Two of them (dé and esté) carry written accents to distinguish them from identical-looking common words. Despite being irregular, these five verbs follow the same negation pattern as all other commands: no + command form.
ser → sea / seanir → vaya / vayansaber → sepa / sepandar → dé / denestar → esté / esténtú: sé · ve · sabe · da · está · negatives: no seas · no vayas · no des · no estés
⚡ The Five Irregular Commands — Complete Reference
SERSeaSean
to be (character/identity)
Sea paciente. Sean puntuales.
Tú: sé / no seas
IRVayaVayan
to go
Vaya a la recepción. Vayan al piso dos.
Tú: ve / no vayas
SABERSepaSepan
to know (a fact)
Sepa que lo ayudamos. Sepan la hora.
Tú: sabe / no sepas
DARDéDen
to give
Dé su ID. Den las gracias.
Tú: da / no des
ESTAREstéEstén
to be (state/location)
Esté tranquilo. Estén listos.
Tú: está / no estés
Why can’t these be built from the yo form? Ser: yo form is soy — dropping -y gives no usable stem. Ir: yo form is voy — same problem. Saber: yo form is sé — already one syllable, no -o to drop. Dar: yo form is doy — again, -y not -o. Estar: yo form is estoy — ends in -y, not -o. All five end in -y in the yo form, not -o, making the vowel swap rule inapplicable. Tú command note: The tú affirmative commands for these verbs are: ser → sé · ir → ve · saber → sabe · dar → da · estar → está. The tú negative commands use the subjunctive form (same stem as Usted + -s): no seas · no vayas · no sepas · no des · no estés.
́ Written Accents on Dé and Esté
📝 Dé (command of dar)
Dé su identificación al guardia. Déme el reporte ahora. No le dé el código a nadie. Without accent: de = the preposition “of/from”
🕑 Esté / Estén (command of estar)
Esté aquí a las ocho en punto. Estén listos para la llamada a las tres. No esté nervioso — está todo bien. Without accent: este = this (demonstrative adjective)
The accent is a disambiguation tool, not just stress:Dé (command: give) vs. de (preposition: of/from). Esté (command: be) vs. este (adjective: this). The accent mark on these two command forms signals to the reader that this is a verb form, not the common preposition or demonstrative. In writing, always include the accent on dé and esté/estén. In speech, context makes the meaning clear, but in formal writing the accent is required.
SER Sea / Sean — Character, Identity, Professional Behavior
UstedSea
UstedesSean
Tú (aff.)Sé
Tú (neg.)No seas
Sea paciente con el cliente — tiene muchas preguntas.
No sea grosero con los pacientes del hospital.
Sea honesto con el doctor sobre sus síntomas.
No sean tan formales entre colegas del mismo equipo.
Sean puntuales para la reunión del lunes.
Sea amable con cada persona que entre a la oficina.
IR Vaya / Vayan — Directions, Locations, Movement
UstedVaya
UstedesVayan
Tú (aff.)Ve
Tú (neg.)No vayas
Vaya a la recepción y llene el formulario.
No vaya por ese camino — está cerrado hoy.
Vayan al segundo piso y busquen la oficina 204.
No vayan sin cita — el doctor solo atiende con cita previa.
Vaya derecho por esta calle y gire a la izquierda.
soy · voy · sé · doy · estoy · yo forms end in -y not -o · vowel swap inapplicable
The vowel swap rule from Section 18.1 requires starting from a yo form that ends in -o (hablo, como, escribo, hago, tengo). All five irregular command verbs have yo forms that end in -y instead: soy, voy, doy, estoy — or are already a single syllable with no -o at all: sé. Because there is no -o to drop, the vowel swap mechanism does not apply. The command forms — sea, vaya, sepa, dé, esté — are unique forms derived from the Old Spanish subjunctive and must simply be memorized. There is no shortcut. The good news: there are only five, they are among the most commonly used verbs in Spanish, and once memorized they follow the same negation pattern as all other commands: no sea, no vaya, no sepa, no dé, no esté.
Memory device — SIDES: The five irregular verbs spell S-I-D-E-S when taken by first letter: Ser · Ir · Dar · Estar · Saber. Usted command forms: sea · vaya · dé · esté · sepa. Tú affirmative command forms: sé · ve · da · está · sabe. Tú negative command forms (use Usted subjunctive + -s): no seas · no vayas · no des · no estés · no sepas. Note: sé (tú command of ser) looks identical to sé (I know, from saber) — context always makes the meaning clear.
✏️ All five irregular commands in one professional sequence:
Sea paciente — el proceso toma tiempo pero lo resolvemos.
Vaya a la ventanilla número tres para continuar.
Sepa que sus datos están completamente protegidos.
Dé su firma en la línea tres del formulario.
Esté tranquilo — el equipo lo atiende ahora mismo.
2. Ser → Sea / Sean — Character and Professional Behavior
sea paciente · sea honesto · sean puntuales · no sea grosero · advice about how to be
Sea/Sean is the command form of ser (to be — permanent or characteristic states). In a professional or medical context, it is used to advise or instruct someone about how to behave, what kind of person to be in this situation, or what attitude to adopt. Sea paciente con el cliente (Be patient with the client). Sea honesto con el doctor (Be honest with the doctor). Sean puntuales para la reunión (Be on time for the meeting). No sea grosero (Don’t be rude). The key distinction between sea (ser) and esté (estar): use sea for character and identity (“be a patient person”), use esté for temporary states (“be calm right now”).
Sea vs. Esté — the ser/estar distinction applied to commands:Sea tranquilo = Be a calm person (character trait — ser). Esté tranquilo = Be calm (right now, in this moment — estar). Tú equivalents:Sé amable (tú — Be kind, character). Está tranquilo (tú — Be calm right now). Negatives: No seas grosero (tú — Don't be rude) · No estés nervioso (tú — Don't be nervous). Note: tú affirmative sé looks like sé (I know) — context always clarifies.
✏️ Sea / Sean in professional and medical context:
Sea paciente — el doctor lo verá en unos minutos.
Sea honesto con el doctor sobre todos sus síntomas.
Sean puntuales — la reunión comienza exactamente a las nueve.
Sea amable con cada persona que entre a esta oficina.
No sea grosero con los pacientes — todos merecen respeto.
3. Ir → Vaya / Vayan — Directions and Movement
vaya a la recepción · vayan al segundo piso · vaya derecho · no vaya por ese camino
Vaya/Vayan is the command form of ir (to go). It is the most commonly used irregular command in any setting where you direct someone to a location or give them movement instructions. Vaya a la recepción, por favor (Go to the reception, please). Vayan al segundo piso (Go to the second floor). Vaya derecho por esta calle (Go straight down this street). No vaya por ese camino (Don’t go that way). In medical and office settings, vaya is essential for directing patients, clients, and visitors to the correct location. Note that although the infinitive is ir and the yo form is voy, the command form is vaya — which actually comes from a different stem entirely (the present subjunctive of ir).
Vaya is also used in the expression “vaya, vaya” and “vaya que…”: Beyond literal directions, vaya appears in colloquial expressions of surprise or emphasis: Vaya, qué interesante (Well, how interesting). In a professional or medical setting, Vaya a la sala de espera is unambiguously a direction command. Tú equivalent: The informal command of ir is ve — one of the most common tú irregular commands. Ve al banco (Go to the bank). Ve a la recepción (Go to reception). Negative: No vayas por ese camino (Don't go that way). Note: ve looks like the 3rd-person present of ver (to see) — context makes the meaning clear.
✏️ Vaya / Vayan for professional directions:
Vaya a la recepción y llene el formulario de registro.
Vayan al segundo piso — la oficina de recursos humanos está a la derecha.
Vaya derecho por esta calle y gire a la izquierda en el semáforo.
No vaya por ese pasillo — está reservado para el personal.
Vayan con la enfermera al cuarto de examen número cuatro.
4. Saber → Sepa / Sepan · Dar → Dé / Den
sepa que · sepan que · dé su ID · den las gracias · déme · no le dé
Sepa/Sepan (from saber) is used to inform someone of a key fact or ensure they are aware of important information. It is almost always followed by que: Sepa que estamos aquí para ayudarle (Know that we are here to help you). Sepan que la oficina cierra a las cinco (Know that the office closes at five). Sepa la verdad sobre el contrato (Know the truth about the contract). It functions as a professional way to announce important information. Dé/Den (from dar) commands someone to hand something over or give something. Dé su identificación al guardia (Give your ID to the guard). Den las gracias al equipo (Give thanks to the team). Déme el reporte (Give me the report — with me attached). No le dé el código a nadie (Don’t give the code to anyone).
Déme — pronoun attached to an irregular command: Pronouns attach to affirmative irregular commands just as they do to regular ones: dé + me = déme (give me). The accent on dé is preserved. Déme el reporte is one of the most-used professional expressions. Tú equivalents: Dar tú command = da. Dame el reporte (informal: give me the report). Da tu ID al guardia (Give your ID to the guard). Negative: No des el código a nadie (Don't give the code to anyone). Saber tú command = sabe. Sabe que estamos aquí (Know that we're here). Negative: No sepas eso todavía (Don't know that yet — less common but grammatically correct).
✏️ Sepa / Sepan and Dé / Den in context:
Sepa que estamos aquí para apoyarle durante todo el proceso.
Sepan que la consulta es completamente gratuita para empleados.
Dé su identificación al guardia en la entrada principal.
Den las gracias al equipo médico por su atención esta semana.
Déme el reporte ahora — lo reviso antes de la reunión.
5. Estar → Esté / Estén — Temporary States and Readiness
Esté/Estén (from estar) commands someone to be in a certain temporary state, at a certain location, or in a state of readiness. Esté tranquilo (Be calm / Stay calm — right now). Estén listos para la llamada (Be ready for the call — at that time). Esté aquí a las ocho (Be here at eight). No esté preocupado (Don’t be worried). The written accent on both esté and estén is required because without it, este is the demonstrative adjective “this” (masculine) and esten is not a standard word but could cause confusion. In speech, stress on the final syllable signals the command; in writing, the accent is essential. Esté covers all the temporary, changeable states that estar is used for: feelings, locations, conditions, readiness.
Esté atento / Estén atentos — a high-frequency workplace command:Esté atento (Pay attention / Be alert) and Estén atentos (plural) are among the most common uses of the estar command in professional settings. Others: Esté disponible (Be available). Estén preparados (Be prepared). Tú equivalents: Estar tú command = está. Está tranquilo (Be calm — tú, temporary state). Está atento (Pay attention — tú). Está aquí a las ocho (Be here at eight — tú). Negative: No estés nervioso (Don't be nervous — tú). Note: tú affirmative está is the same form as the 3rd-person present tense — context makes it clear when it is a command.
✏️ Esté / Estén in professional and medical settings:
Esté tranquilo — el procedimiento es rápido y completamente indoloro.
Estén listos para la llamada de conferencia a las tres de la tarde.
Esté aquí a las ocho en punto — no podemos esperar.
No esté nervioso — el doctor tiene veinte años de experiencia.
Estén atentos durante la presentación — hay información importante.
📌 Key Rules — Irregular Commands (Usted, Ustedes & Tú) at a Glance
The five irregular Usted/Ustedes commands must be memorized: ser → sea/sean · ir → vaya/vayan · saber → sepa/sepan · dar → dé/den · estar → esté/estén. Memory aid: SIDES (Ser, Ir, Dar, Estar, Saber).
The five irregular Tú affirmative commands: ser → sé · ir → ve · saber → sabe · dar → da · estar → está. These are the standard tú imperative forms, not derived from the vowel swap.
The five irregular Tú negative commands use the Usted command stem + -s: no seas · no vayas · no sepas · no des · no estés. The same pattern as all tú negatives from Section 18.1.
Why they are irregular (Usted/Ustedes): All five have yo forms ending in -y (soy, voy, doy, estoy) or are monosyllabic (sé), making the vowel swap rule inapplicable.
Written accents on dé and esté/estén: Required to distinguish dé (give) from de (of/from) and esté (be) from este (this). Always write the accent in formal documents.
Negatives follow the same rule as all commands: no + command form. No sea · no vaya · no sepa · no dé · no esté (Usted). No seas · no vayas · no sepas · no des · no estés (Tú). The form itself does not change in negatives.
Pronouns attach to affirmative irregular commands: Dé + me = déme (Usted) · Da + me = dame (Tú). The accent rules from Section 18.2 apply equally here.
Sea (ser) vs. Esté (estar): Sea/Sé = be (character/identity, permanent). Esté/Está = be (state/location/readiness, temporary). Sea paciente = be a patient person. Esté tranquilo = be calm right now.
Homonym alert:Sé (tú command of ser) = sé (I know, from saber). Both are written the same. Context always clarifies which is intended.
Shadow & Speak — Section 18.3-A
Listen to each irregular command, then repeat aloud during the countdown.
Sentences 1–5 drill all five irregular commands in one sentence each — one per verb — to establish the five forms as distinct units. Sentences 6–10 drill sea/sean in varied professional and medical contexts covering both character advice and negative prohibitions. Sentences 11–15 drill vaya/vayan for giving directions to locations, routes, and specific offices or floors. Sentences 16–20 drill sepa/sepan and dé/den together as complementary information-and-handover commands. Sentences 21–25 drill esté/estén for temporary states, readiness, and location, including the sea/esté contrast. Sentences 26–30 drill Tú irregular commands — sé, ve, da, está affirmative and no seas, no vayas, no des, no estés negative — contrasting them directly with the Usted forms.
How to Shadow & Speak
Step 1 — Name the verb before speaking: Before each sentence, name the infinitive: “ir,” “ser,” etc. This keeps the link between infinitive and command form active, rather than letting the irregular form become a disconnected fixed phrase. Goal: the chain ir → voy → vaya should fire automatically.
Step 2 — Produce the plural form after each singular: After each singular command sentence, immediately produce the plural equivalent. After Vaya a la recepción, say Vayan a la recepción. This doubles the exposure to both forms and prevents memorizing only the singular.
Step 3 — Sea vs. Esté contrast drill: For sentences using sea or esté, pause and ask yourself: “Is this a permanent character trait (sea) or a temporary state (esté)?” Verbalizing the distinction while hearing the sentence reinforces the ser/estar logic at the command level.
Study Tips
The SIDES chain drill: Write the five irregular commands as one rapid chain: sea · vaya · dé · esté · sepa. Drill until you can produce them in under five seconds. Then produce their plurals: sean · vayan · den · estén · sepan. Then produce a sentence for each. This three-layer drill (form → plural → sentence) is the fastest path to automatic recall.
The negative conversion drill: Take each affirmative form and produce its negative: Sea → No sea · Vaya → No vaya · Dé → No dé · Esté → No esté · Sepa → no applies well here. Practice until switching between affirmative and negative is instantaneous.
Real-world anchoring: Match each irregular command to one specific professional scenario you encounter regularly. Sea paciente = talking to a waiting client. Vaya al segundo piso = directing someone in your building. Sepa que… = announcing important information. Dé su ID = at a security checkpoint. Esté listo = before a meeting. Anchoring to real scenarios makes the forms retrievable in the moment they are needed.
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Quiz — Section 18.3-B
Choose the correct answer. 20 questions drawn randomly from a pool of 30.