Saber — "to know" in the sense of knowing facts, information, or how to do something — is one of the small handful of Spanish verbs that is irregular in almost every tense it has. The yo form sé is unique in the language (one consonant, one vowel, one written accent that distinguishes it from the reflexive pronoun se). The preterite is built on the u-stem sup- (supe, supiste, supo) — and that same preterite carries a meaning shift English speakers reliably miss: supe doesn't usually mean "I knew" but "I found out, I learned". The future drops the -e- of the infinitive (sabré, not saberé), matching poder/podré, querer/querré, haber/habré. And the present subjunctive replaces the b of the stem with p (sepa, sepas, sepa), an alternation that exists nowhere else in the paradigm.
This is the second of the two Spanish verbs translated as English know. The other is conocer — to be acquainted with a person, a place, or a work. The line between them is one of the first sharp distinctions every English speaker has to internalize, and the page on conocer covers the contrast in depth. Here we focus on saber itself.
Non-finite forms
| Form | Spanish | English |
|---|---|---|
| Infinitivo | saber | to know |
| Infinitivo compuesto | haber sabido | to have known |
| Gerundio | sabiendo | knowing |
| Gerundio compuesto | habiendo sabido | having known |
| Participio | sabido | known |
The participle and the gerund are both perfectly regular — the irregularities of saber are concentrated in the finite forms. Note the spelling: sabiendo, with b, not v.
Indicative — simple tenses
Presente
| yo | tú | él/ella/usted | nosotros | vosotros | ellos/ellas/ustedes |
|---|---|---|---|---|---|
| sé | sabes | sabe | sabemos | sabéis | saben |
The yo form sé is the only truly irregular form in the present indicative. The other five forms attach regular -er endings to the stem sab-. The written accent on sé is obligatory — it distinguishes the verb form from the pronoun se (which has no accent). The pair sé / se is one of the most-confused pairs in written Spanish, even among native speakers, and getting it wrong is conspicuous in writing.
No sé qué hacer con tanta gente en casa.
I don't know what to do with so many people at home.
¿Sabéis a qué hora cierra el supermercado los domingos?
Do you all know what time the supermarket closes on Sundays?
Pretérito perfecto simple
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| supe | supiste | supo | supimos | supisteis | supieron |
The preterite stem is sup-, with the classic "strong" (unstressed-ending) pattern shared by poder/pude, poner/puse, tener/tuve, haber/hube, andar/anduve, estar/estuve. The stress falls on the stem in yo and él — hence supe and supo, both unaccented.
Critical meaning shift: in the preterite, saber most commonly means "to find out, to learn" — the moment knowledge was acquired, not a continuous state of knowing. Lo supe ayer means "I found out yesterday," not "I knew yesterday." For the state of knowing in the past, Spanish uses the imperfect sabía. This contrast — preterite = acquisition of knowledge, imperfect = state of knowledge — is one of the cleanest illustrations of the imperfecto/pretérito distinction in the entire verb system.
Supe lo de tu padre por el grupo del pueblo, lo siento muchísimo.
I found out about your father from the village group chat — I'm really sorry.
No supimos nada del accidente hasta dos días después.
We didn't find out about the accident until two days later.
Pretérito imperfecto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| sabía | sabías | sabía | sabíamos | sabíais | sabían |
The imperfect is perfectly regular for -er verbs, built on the stem sab-. This is the form to use for the state of knowing in the past — what you knew without specifying when you learned it.
Yo no sabía que tenías hermanos, nunca me lo habías dicho.
I didn't know you had siblings — you'd never told me.
De niños sabíamos los nombres de todos los jugadores del Madrid de memoria.
As kids we knew the names of all the Madrid players by heart.
Futuro simple
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| sabré | sabrás | sabrá | sabremos | sabréis | sabrán |
The future stem is sabr- — the -e- of the infinitive drops. This dropped-vowel pattern is shared with caber/cabré, haber/habré, poder/podré, querer/querré. The endings -é, -ás, -á, -emos, -éis, -án are universal.
The future of saber is also one of the most idiomatic ways to express conjecture or uncertainty about the present in Spanish: ¿Quién sabrá lo que pasó? — "Who could know what happened?" / "I wonder who knows what happened." This use is core spoken Spanish and not literary at all.
Cuando vuelvas del médico me lo contarás todo, ya sabré yo qué hacer.
When you get back from the doctor you'll tell me everything, and I'll know what to do.
¿Cómo sabré si me han contestado el correo?
How will I know if they've replied to my email?
Condicional
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| sabría | sabrías | sabría | sabríamos | sabríais | sabrían |
Same sabr- stem as the future, with conditional endings -ía, -ías, -ía, -íamos, -íais, -ían.
Yo no sabría decirte, eso pregúntaselo al jefe.
I really couldn't tell you — ask the boss.
Indicative — compound tenses
All compound tenses pair haber with the regular participle sabido.
Pretérito perfecto compuesto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| he sabido | has sabido | ha sabido | hemos sabido | habéis sabido | han sabido |
In peninsular Spanish this is the default tense for news learned earlier today: Esta mañana he sabido que… ("This morning I found out that…"). Like the simple preterite, he sabido carries the inchoative reading of finding out, not the stative one of having known.
Acabo de saberlo ahora mismo, he sabido lo de la huelga por la radio.
I just found out right now — I heard about the strike on the radio.
Pretérito pluscuamperfecto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| había sabido | habías sabido | había sabido | habíamos sabido | habíais sabido | habían sabido |
Si lo hubieras dicho antes, ya habríamos sabido qué traer.
If you'd said earlier, we'd already have known what to bring.
Futuro compuesto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| habré sabido | habrás sabido | habrá sabido | habremos sabido | habréis sabido | habrán sabido |
Condicional compuesto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| habría sabido | habrías sabido | habría sabido | habríamos sabido | habríais sabido | habrían sabido |
De haberlo sabido, no habría venido en absoluto.
Had I known, I wouldn't have come at all.
Subjunctive — simple tenses
Presente de subjuntivo
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| sepa | sepas | sepa | sepamos | sepáis | sepan |
The present subjunctive uses the stem sep- — the b of sab- becomes p, and the -er opposite-vowel endings are applied. This alternation has no other source in the paradigm: sé (yo present indicative) does not generate it, the way hago → haga does. Sepa simply has to be memorised. It is one of the six fully suppletive subjunctive paradigms in Spanish (sea, esté, dé, haya, vaya, sepa).
Quiero que sepáis que estoy muy orgulloso de vosotros.
I want you all to know I'm very proud of you.
Que yo sepa, mañana no hay clase.
As far as I know, there's no class tomorrow.
The set phrase que yo sepa ("as far as I know") is everyday spoken Spanish — used constantly to hedge a claim. Learn it as a whole unit.
Imperfecto de subjuntivo (-ra / -se)
| yo | tú | él | nosotros | vosotros | ellos | |
|---|---|---|---|---|---|---|
| -ra | supiera | supieras | supiera | supiéramos | supierais | supieran |
| -se | supiese | supieses | supiese | supiésemos | supieseis | supiesen |
Both sets are built on the preterite stem sup-. The -ra forms dominate in spoken Spain; -se is more formal but still fully current in writing.
Si supiera lo que me dices, no habría reaccionado así.
If I knew what you're telling me, I wouldn't have reacted like that.
Subjunctive — compound tenses
Pretérito perfecto de subjuntivo
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| haya sabido | hayas sabido | haya sabido | hayamos sabido | hayáis sabido | hayan sabido |
Me extraña que no hayas sabido nada de él en todo el verano.
It surprises me you haven't heard anything from him all summer.
Pluscuamperfecto de subjuntivo
| yo | tú | él | nosotros | vosotros | ellos | |
|---|---|---|---|---|---|---|
| -ra | hubiera sabido | hubieras sabido | hubiera sabido | hubiéramos sabido | hubierais sabido | hubieran sabido |
| -se | hubiese sabido | hubieses sabido | hubiese sabido | hubiésemos sabido | hubieseis sabido | hubiesen sabido |
Si hubiéramos sabido que venías, te habríamos esperado para cenar.
If we'd known you were coming, we'd have waited for you to have dinner.
Imperative
| Form | Affirmative | Negative |
|---|---|---|
| tú | sabe | no sepas |
| usted | sepa | no sepa |
| nosotros | sepamos | no sepamos |
| vosotros | sabed | no sepáis |
| ustedes | sepan | no sepan |
The imperative of saber is rarely used in everyday speech — you don't tell someone "know!" The forms that do occur are the usted / ustedes affirmative (sepa, sepan), commonly heard as a formal way to introduce information: Sepa usted que… ("I'd have you know that…", with a slight edge). The tú form sabe is essentially never spoken; sabed survives in formal writing or set expressions like sabed que….
Sepa usted que esto no quedará así.
I'd have you know this isn't going to end here. (formal, slightly confrontational)
Saber + infinitive — "to know how to"
The construction saber + infinitive is the standard way to express "to know how to do something" in Spanish. Critically, there is no cómo between saber and the infinitive.
- Sé nadar. — I know how to swim.
- No sabe conducir. — He doesn't know how to drive.
- ¿Sabes tocar la guitarra? — Do you know how to play the guitar?
English speakers reflexively insert cómo: Sé cómo nadar. This is wrong as a calque of "I know how to swim" — cómo in saber cómo introduces a different nuance ("the way in which"), and the form is restricted to contexts where you are emphasising the manner: No sé cómo lo hace (I don't know how he does it / by what means). For the basic skill claim, drop cómo.
No sabía que sabías cocinar tan bien, esto está delicioso.
I didn't know you knew how to cook so well — this is delicious.
Mi abuela sabe hablar cuatro idiomas y nunca fue al colegio.
My grandmother knows how to speak four languages and never went to school.
"To taste" — the other saber
Saber has a second meaning that learners often miss entirely: to taste (of), used intransitively with a.
- Esto sabe a limón. — This tastes of lemon.
- Sabe raro. — It tastes strange.
- No me sabe a nada. — It doesn't taste of anything to me.
This usage is fully current in everyday Spanish and is the only way to say taste in this sense (the verb probar is to try, to taste-test, not to taste of). The construction is also the source of the idiom saber a poco — "to leave you wanting more" (literally, "to taste like little"), used for food, films, holidays, anything that ends too soon.
Este gazpacho sabe a tomate de verdad, no como los del súper.
This gazpacho tastes of real tomato, not like the ones from the supermarket.
Las vacaciones me han sabido a poco, ¿a ti no?
The holiday went by too fast for me — didn't it for you?
High-frequency collocations from peninsular Spanish
| Phrase | Translation |
|---|---|
| que yo sepa | as far as I know |
| no saber qué hacer | not to know what to do |
| saber de buena tinta | to know on good authority |
| saber de qué va la cosa | to know what something is about |
| vete a saber / a saber | (informal) who knows |
| ¡yo qué sé! | (informal) how should I know! |
| saber a poco | to leave you wanting more |
| saber latín | (idiom) to be very shrewd / streetwise |
| no saber ni jota (de algo) | not to know the first thing (about something) |
¡Yo qué sé! is one of the most useful conversational reflexes in spoken Spain — it covers "how should I know," "your guess is as good as mine," and "I have no idea" all at once. Equally common: vete (tú) a saber — "who knows," used as a resigned shrug.
¿Dónde habrá puesto las llaves esta vez? ¡Yo qué sé!
Where could he have put the keys this time? Beats me!
No sabe ni jota de fútbol, pero se lo pasa pipa en el campo.
He doesn't know the first thing about football, but he has a great time at the stadium.
Common Mistakes
❌ Sé cómo nadar muy bien.
With saber + activity, drop cómo. Sé nadar muy bien.
✅ Sé nadar muy bien.
I know how to swim very well.
❌ Yo sabí la respuesta ayer.
The preterite of saber is irregular: yo supe, not sabí. And in this context, supe means 'I found out' — for 'I knew the answer,' you want the imperfect: sabía.
✅ Yo sabía la respuesta ayer.
I knew the answer yesterday.
❌ Quiero que sabes la verdad.
The present subjunctive of saber uses the stem sep-: sepa, sepas, sepa, sepamos, sepáis, sepan. 'Quiero que sepas la verdad.'
✅ Quiero que sepas la verdad.
I want you to know the truth.
❌ Conozco la respuesta de esta pregunta.
For knowing a fact, information, or an answer, Spanish uses saber, not conocer. Conocer is for being acquainted with people, places, and works.
✅ Sé la respuesta a esta pregunta.
I know the answer to this question.
❌ Se que estás cansado.
The yo present indicative of saber carries a written accent: sé, to distinguish it from the pronoun se.
✅ Sé que estás cansado.
I know you're tired.
Key Takeaways
- Saber has five irregular zones: sé (the unique yo present), sep- (entire present subjunctive), sup- (preterite and imperfect subjunctive), sabr- (future and conditional), and otherwise the regular sab- stem.
- In the preterite, saber most often means "to find out, to learn" — supe is the moment of acquiring knowledge. For the state of knowing in the past, use the imperfect sabía.
- The construction saber + infinitive means "to know how to do" — no cómo needed.
- Saber a
- noun means "to taste of" — a separate, fully alive sense of the verb.
- Saber is for facts, information, and skills. Conocer is for being acquainted with people, places, and works.
- The written accent on sé (yo present indicative) is obligatory and distinguishes the verb form from the pronoun se.
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Start learning Spanish→Related Topics
- conocerA1 — Full conjugation reference for conocer — to know people, places and things by acquaintance. Includes the c→zc yo form (conozco), every simple and compound tense, the all-important meaning shift in the preterite (conocí = met for the first time), and the saber-vs-conocer distinction.
- Pretérito con raíz en -u-: estar, tener, poder, poner, saberB1 — The strong-preterite family whose stem warps to -u-: estuve, tuve, pude, puse, supe — sharing one set of unaccented endings and producing several of the highest-frequency verbs in spoken Spanish.
- Futuro: raíces irregularesB1 — The twelve Spanish verbs with irregular future stems — tendr-, pondr-, saldr-, vendr-, valdr-, podr-, sabr-, cabr-, querr-, habr-, har-, dir- — grouped by pattern, with the same endings as regular verbs and the bonus that these stems also power the conditional.
- Subjuntivo presente: cambios vocálicosB1 — Stem-changing verbs in the present subjunctive — the boot pattern for -ar/-er verbs and the extra wrinkle that hits -ir verbs in nosotros and vosotros.
- poderA1 — Full conjugation reference for poder (can, to be able to) — one of the most-used verbs in Spanish, with an o>ue stem change in the present, a u-stem preterite (pude, pudo), a dropped-vowel future (podré), and a meaning shift in the preterite (managed to). Covers the modal uses, the polite ¿puedes…? / ¿podrías…?, the every-day no puedo más, and the peninsular vosotros forms.