20 Spanish Expressions That Mean “I Don’t Know” [Audio]
“I don’t know” in Spanish is probably an expression you’ve used at least once or twice.
Doubt and insecurity are the same in every language. Not knowing something can sometimes be frustrating and poses a challenge. These are tough feelings to escape when it comes to learning.
However, when it comes to Spanish you’ll be amazed by the different and unique ways you can say it.
If you’ve ever felt unsure or lost in Spanish conversation, this fun blog post is just for you!
Let others know when you have no idea with this insightful list of 20 expressions that mean “I don’t know” in Spanish.
How To Say “I Don’t Know” in Spanish
No sé is the prefered and go-to way of saying “I don’t know” in Spanish. This expression is a wildcard for many conversations.
You can use it in different scenarios and situations:
- As what to say when you don’t know what to say.
- When you don’t know anything.
- When you don’t understand.
- When you don’t know an answer.
No sé comes from the verb saber (to know).
Review the Saber Conjugation.
Doubt and no saber (not knowing) can feel overpowering.
However, when you get the confidence to ask once again or express that you don’t know something, a new, honest learning process begins.
As a language learner you also overcome insecurity and start getting familiarized with new concepts, people, places, among others.
Do you get the jitters when you’re speaking Spanish? Learn how to overcome feeling shy or nervous when you speak Spanish.
What To Say Instead of “I Don’t Know” in Spanish
Spanish is highly diverse and usually has several peculiar ways to say something. Being a romance language, it’s highly expressive and deep when it comes to feelings, especially doubt.
Expand your vocabulary with these new 20 expressions for saying “I don’t know” in Spanish.
1. No tengo idea
No tengo idea is a Spanish expression that stands in English for “I have no idea.”
Use this expression for saying I don’t know in Spanish when you don’t have an answer to a question or when you’re literally lost in conversation.
No tengo idea is perfect for saying you feel clueless.
No tengo idea de que estás hablando.
I have no idea what you’re talking about.
No tengo idea de lo que estás diciendo.
I have no idea what you’re saying.
No tengo idea de qué pasó.
I have no idea what happened.
2. No estoy seguro
No estoy seguro translates in English to “I’m not sure.”
Use it as I don’t know in Spanish when you have doubts or are second-guessing yourself. It works whenever they ask you a question you don’t know the answer to, or you can also use it to let someone know you feel unsure.
No estoy seguro de si voy a ti.
I’m not sure if I’m going.
No estoy seguro de lo que dices.
I’m not sure about what you’re saying.
No estoy seguro de nada.
I’m not sure about anything.
3. Quién sabe
Quién sabe translates in English to “who knows.”
It’s a common expression for saying I don’t know in Spanish without being too specific. Use it when a person asks you what’s going on, what happened, or when they ask for your opinion, and you just don’t know the answer to something.
Quién sabe si lograré ir.
Who knows if I’ll be able to go.
Honestamente, quién sabe.
Honestly, who knows.
Quién sabe, yo la verdad no.
Who knows, I really don’t.
4. Déjame ver y te aviso
Déjame ver y te aviso stands for “let me see and I’ll let you know” in English. It can also mean “Let me check before”.
Use it to say I don’t know in Spanish in any situation where you don’t have an immediate answer, but are planning to give it in the future.
You can also use it for when you want to confirm something before giving any wrong information.
Déjame ver si puedo ir y te aviso.
Let me see if I can go and I’ll let you know.
Déjame ver y te aviso, tengo que preguntar.
Let me see and I’ll let you know, I have to ask.
Déjame ver si alguien sabe y te aviso.
Let me see if anyone knows and I’ll tell you.
5. No sabría decirte
No sabría decirte is a popular way of saying I don’t know in Spanish. It means “I couldn’t tell you.”
Use it when you don’t know the specifics of why something happened or when you simply don’t know what to say.
No sabría decirte is a fantastic response for when the outcome of a situation doesn’t depend on what you say or do.
No sabría decirte por qué decidió no venir tu hermana.
I couldn’t tell you why your sister decided not to come.
No sabría decirte si lo logro hoy.
I couldn’t tell you if I’ll make it today.
No sabría decirte nada.
I couldn’t tell you anything.
6. Tengo mis dudas
Tengo mis dudas means “I have my doubts.”
Spanish speakers use it to express when they feel unsure or don’t know if something is 100% true or not. It’s also used for saying I don’t know in Spanish when you have an idea but aren’t entirely sure if it’s right or not.
Se ve bien, pero tengo mis dudas si va a funcionar o no.
It looks okay, but I have my doubts if it’ll work or not.
Tengo mis dudas de por qué no estás aquí.
I have my doubts about why you’re not here.
Tal vez es cierto, pero yo tengo mis dudas.
Maybe it’s true, but I have my doubts.
7. Tengo que pensarlo
Tengo que pensarlo means “I have to think about it” in English.
Use it to say I don’t know in Spanish when you don’t know how to respond or simply don’t know what to say. Some Spanish speakers use it as a polite way of saying “maybe” instead of a dry “I don’t know.”
Tengo que pensarlo antes de darte una respuesta.
I have to think about it before giving you an answer.
Tal vez sí, pero tengo que pensarlo primero.
Maybe, but I have to think about it first.
Tengo que pensarlo, me falta tiempo para decidir.
I have to think about it, I need time to decide.
Do you need time to think about it? Learn 50+ Time Expressions in Spanish.
8. No tengo certeza
The expression No tengo certeza has a similar meaning to the expression no estoy seguro. We use it to express uncertainty, doubt, and simply not knowing.
In English it means “I don’t have certainty.” It’s an expression that comes off as formal and can be applied to work environments or gatherings.
No tengo certeza de sus motivos.
I don’t have certainty of their motives.
No tengo certeza de qué tengo que hacer.
I don’t have certainty of what I have to do.
No tengo certeza de lo que dices.
I don’t have certainty of what you’re saying.
9. Nadie sabe
Nadie sabe is a common expression for saying I don’t know in Spanish. It means “nobody knows” in English.
It’s an informal expression that can be used in casual scenarios. It doesn’t have to be addressed to anybody specifically, it can be used as an affirmation of doubt.
¿Quién hizo esto? ¿Acaso nadie sabe?
Who did this? Does anybody know?
Ya no dijeron nada así que nadie sabe.
They didn’t say anything so nobody knows.
Aquí nadie sabe.
Nobody knows here.
The expression saber comes from the Spanish verb of the same name. Spanish speakers use it in this case without conjugating it. It has a similar meaning to “who knows” in English.
It’s more a response to when you don’t know anything about a matter in question. Use it as a response only in informal and casual situations with people you already know.
Saber qué pasó.
Who knows what happened.
Saber quién es él, no lo conozco.
Who knows who he is, I don’t know him.
Saber si las cosas serán diferentes esta vez.
Who knows if things will be different this time.
11. No entiendo nada
No entiendo nada is used to say I don’t know in Spanish but it’s more inclined to not understanding. It means “I don’t understand anything” in English.
Use it for situations when you’re clearly not grasping what goes on around you. It’s particularly useful for language learners when they struggle.
No entiendo nada de lo que dices.
I don’t understand anything you’re saying.
No entiendo nada, ¿puedes hablar más lento?
I don’t understand anything, can you talk more slowly?
¿Puedes repetirlo? No entiendo nada.
Can you repeat it? I don’t understand anything.
12. No te comprendo
No te comprendo is often used to say I don’t know in Spanish. The expression stands for “I can’t understand you” in English.
We use it whenever you can’t process instructions and are lost in someone’s explanation or conversation. The verb comprender (comprehend) is formal, making this an expression you can use in a work environment.
No te comprendo, habla más despacio por favor.
I can’t understand you, talk more slowly please.
Dijiste muchas cosas, no te comprendo.
You said many things, I can’t understand you.
No te comprendo, cambias mucho de parecer.
I can’t understand you, you change your mind too much.
13. No te estoy siguiendo
No te estoy siguiendo means “I’m not following you.” It’s an ideal expression to indicate you don’t know in Spanish and that you got lost in a conversation.
This phrase is perfect for when people speak too fast or share large amounts of details. Use it when people lose your interest and confuse you.
Es mucha información, no te estoy siguiendo.
It’s a lot of information, I’m not following you.
¿Y luego qué pasó? No te estoy siguiendo.
And then what happened? I’m not following you.
No te estoy siguiendo, son muchos detalles.
I’m not following you, there are too many details.
14. ¿Qué quieres decir con eso?
The expression ¿qué quieres decir con eso? means “what do you mean by that?”
Use it in it’s form of question when you don’t understand or don’t know why a person is saying what they’re saying.
You can also use it if you’re hesitant about agreeing with someone. It’s good for double-checking when you can’t understand.
Te escuché, pero ¿qué quieres decir con eso?
I heard you but what do you mean by that?
¿Qué quieres decir con eso? Explícame de nuevo.
What do you mean by that? explain it to me again.
Me dijiste aunque no sé qué quieres decir con eso.
You told me but I don’t know what you mean by that.
15. No logro captar
No logro captar is used for when you can’t quite grasp, or fully understand what is going on around you.
We also use it when you can’t comprehend a particular explanation. We often use it after many attempts to understand what’s happening. The English translation is “I can’t catch.” It can also mean “I don’t seem to catch.”
No logro captar lo que estás diciendo.
I can’t catch what you’re saying.
Explícame otra vez por favor, no logro captar.
Explain it to me again please, I can’t seem to catch it.
Ya trate y no logro captar.
I already tried and can’t seem to catch it.
16. ¿Cómo así…?
The expression ¿cómo así? is informally used as a way to ask “what do you mean” or “how’s that?”
It applies to infinite scenarios as a casual expression or filler word. You can use it to respond to situations where you’re confused about what’s happening. Use it to ask about actions and events where you don’t understand how they unfolded.
¿Cómo así que no sabía lo que te pasó?
How is it that I didn’t know what happened to you?
No entiendo, ¿cómo así?
I don’t understand, how is that?
¿Cómo así? Dímelo otra vez por favor.
How’s that? Tell me again please.
17. Otra vez, por favor
Otra vez por favor literally translates in English to “again please.” In Spanish, we can use it as a way of saying “pardon me” or “come again?”
With this expression you ask people to please repeat what just happened. Spanish speakers have a fantastic use for this expression as it can apply to whenever you have trouble with your listening and pronunciation skills.
Dilo otra vez por favor.
Say it again please.
Hablas muy rápido, dilo otra vez por favor.
You talk too fast, say it again please.
Me perdí la historia, cuéntala otra vez por favor.
I missed the story, tell it again please.
18. ¿De qué hablas?
¿De qué hablas? is useful when you don’t know in Spanish what someone is talking about.
This expression is used to indicate doubt and confusion. It translates in English to “what are you talking about?” You can use it to join a casual conversation with people you already know.
¿De qué hablas? me perdí la plática.
What are you talking about? I missed the conversation.
¿De qué hablas? No creo que haya pasado eso.
What are you talking about? I don’t believe that happened.
No estoy segura de qué hablas.
I’m not sure what you’re talking about.
19. No me queda claro
No me queda claro is a commonly used Spanish expression. It means “it’s not clear to me” in English.
You can use it to express doubt after hearing a fact or story once already. It’s a polite and proper way of telling someone you need further info, more details, and more explaining.
No me queda claro lo que dices.
What you’re saying isn’t clear to me.
No me queda claro qué pasó.
It’s not clear to me what happened.
No me queda claro si eres el mismo.
It’s not clear to me if you’re the same.
Learn for your next conversations 10 Ways to Use ‘Mismo’.
20. Sigo sin entender
Sigo sin entender is a simple way of saying I don’t know in Spanish. It means “I still can’t understand” in English.
You can use it after asking questions or explanations several times without understanding the answer. It’s an expression for indicating your confusion, doubt, and lack of understanding after many attempts.
Sigo sin entender de qué hablas.
I still don’t understand what you’re talking about.
Sigo sin entender qué pasó ayer.
I still don’t understand what happened yesterday.
Sigo sin entender la historia.
I still don’t understand the story.
Spanish Idioms: Not Knowing or Understanding
A Spanish idiom is an expression natural to only native speakers. Idioms have a non-literal meaning attached to them. However, native speakers easily understand them due to their intuitive use and familiarity.
Here are some example idioms for saying I don’t know in Spanish.
No te caché
No te caché can mean “I didn’t get that” or “I didn’t understand you.”
It’s an informal expression used in several Central American countries.
No te caché lo que dijiste.
I didn’t get what you said.
Me mata la curiosidad
Me mata la curiosidad literally translates to “curiosity is killing me.” It’s a way of expressing your eagerness to understand and know why something happened.
Me mata la curiosidad, quiero saber qué más pasó ayer.
Curiosity is killing me. I want to know what else happened yesterday.
Top off this lesson with 20+ Expressions Using ‘Más’ and ‘Menos’.
No le agarro la onda
No le agarro la onda is often used in Mexico. It’s an idiom that stands for “I can’t seem to get it” or “I don’t know how to do that.”
No le agarro la onda a cocinar.
I can’t seem to get how to cook.
No estamos en la misma página
No estamos en la misma página means “we’re not on the same page.”
We use it when we have different understandings of what’s going on with another person.
No estamos en la misma página, yo siento que las cosas pasaron de diferente manera.
We’re not on the same page, I feel like things went down differently.
More Ways To Say “I Don’t Know”
The expression no se for saying I don’t know in Spanish can be used for talking about people, events, places, objects, and many different subjects. It ‘s usually followed by quien (who), que (what), cuando (when), cual (which), and como (how).
Let’s see the expression no se connected to different clauses using these essential words.
No sé quién eres tú.
I don’t know who you are.
No sé qué decirte.
I don’t know what to say.
No sé qué es eso.
I don’t know what that is.
No sé cuándo llegarás.
I don’t know when you’re arriving.
No sé cuál es ese.
I don’t know which one that is.
No sé cómo se dice.
I don’t know how to say it.
Learn Other Spanish Expressions and Idioms
When you master Spanish expressions, your confidence as a Spanish learner grows and you start using new vocabulary naturally.
Sign up for a free trial class with our teachers from Guatemala. You’ll be amazed with the results our different programs can give you. Take your communication skills to the next level and take on the challenge of learning Spanish with the best of the best.
Join one of the 40,000 classes that we teach each month and you can experience results like these
“HSA offers very affordable, quality, one on one classes with a native speaker. My son has greatly benefited from taking classes. We have seen his confidence increase as well as his pronunciation improve, because he learns from a native Spanish speaker. HSA has quick, personal customer service. Our family has been very pleased with our experience so far!”
– Erica P. Parent of 1
“Getting to know wonderful teachers who care about me and my growth in language and education. Evelyn Gomez and Erick Cacao are two of the most extraordinary people I have ever met, and talking with them in Spanish at the beginning of classes is always so fulfilling and greatly contributes to my happiness, joy, and wellbeing.”
“My Son, Heath, is taking the classes. He’s been with Luisa the entire time and we absolutely love her. She is always patient and is a great teacher. Heath’s dad speaks Spanish so they get to have little conversations.”
– William R, Parent of 3
Ready to learn more Spanish vocabulary? Check these out!
- Spanish Words with Multiple Meanings in Latin America
- World Mental Health Day: A Vocabulary Guide for Mental Health Workers
- Expressing Appreciation in Spanish on World Teachers’ Day
- Art and Painting Vocabulary in Spanish
- Fall En Español: Exploring Autumn Activities for Kids
- Words You Need to Know: Common Spanish Vocabulary
- Blueprints en Español: Construction Spanish Made Simple
- Mastering Hard Words in Spanish
- 29 Cool and Catchy Spanish Phrases To Use With Friends [+Audio] - January 8, 2023
- A Fun Kids’ Guide to Opposites in Spanish (Free Lesson and Activities) - December 29, 2022
- 10 Fun Spanish Folk Tales for Kids - December 10, 2022