Meaning
Used to express lack of knowledge.
Cultural Background
Spaniards are often very direct. While 'No lo sé' is common, you will very frequently hear 'Ni idea' (Not an idea) among friends, which isn't considered rude. In Mexico, people might use 'Quién sabe' (Who knows) as a more idiomatic and slightly softer alternative to 'No lo sé'. Argentines might use 'Qué sé yo' (What do I know) to express that they don't know and perhaps don't care, or as a filler phrase.
The 'Lo' is your friend
Including 'lo' makes you sound more like a native speaker than just saying 'No sé'.
Accent matters
Always write 'sé' with an accent. 'Se' (without accent) is a pronoun used in 'Se vende' or 'Se lava'.
Meaning
Used to express lack of knowledge.
The 'Lo' is your friend
Including 'lo' makes you sound more like a native speaker than just saying 'No sé'.
Accent matters
Always write 'sé' with an accent. 'Se' (without accent) is a pronoun used in 'Se vende' or 'Se lava'.
Test Yourself
Fill in the missing pronoun.
No ___ sé.
'Lo' is the neutral direct object pronoun used with 'saber'.
Which is the most natural way to say 'I don't know' in a neutral setting?
Select the best option:
'No lo sé' is the standard, grammatically correct form.
Match the response to the question.
¿A qué hora es la fiesta?
When asked for a specific time you don't know, 'No lo sé' is the appropriate response.
Complete the dialogue.
A: ¿Dónde están mis llaves? B: Lo siento, ___.
Even if 'llaves' is feminine plural, the phrase 'No lo sé' uses the neutral 'lo' to refer to the *fact* of their location.
🎉 Score: /4
Visual Learning Aids
Practice Bank
4 exercisesNo ___ sé.
'Lo' is the neutral direct object pronoun used with 'saber'.
Select the best option:
'No lo sé' is the standard, grammatically correct form.
¿A qué hora es la fiesta?
When asked for a specific time you don't know, 'No lo sé' is the appropriate response.
A: ¿Dónde están mis llaves? B: Lo siento, ___.
Even if 'llaves' is feminine plural, the phrase 'No lo sé' uses the neutral 'lo' to refer to the *fact* of their location.
🎉 Score: /4
Frequently Asked Questions
3 questionsYes, 'No sé' is very common and perfectly correct in spoken Spanish.
Yes, it is neutral and polite. To be extra polite, add 'Lo siento' (I'm sorry) before it.
Because it refers to a 'concept' or 'fact', which is always treated as masculine neutral in Spanish.
Related Phrases
No tengo ni idea
similarI don't have the slightest idea
Quién sabe
similarWho knows
No estoy seguro
similarI'm not sure
