Italian Phrase of the Week: Non lo so. (I don’t know.)

If somebody asks you a question and you simply can’t think of the answer, the best (and most honest) way to respond is by saying I don’t know.

In Italian, this phrase translates as (Io) non lo so. It breaks down as follows:

Io (I) + non (negation) + lo (it) + so (know, first person).

IPA: /nón ló só/

The reason I’ve put io (I) into brackets is because in Italian and many other languages, subject pronouns are optional if the subject is made unambiguous by the context – in this case, the conjugated verb so (I know).

Io only becomes necessary for emphasis or if the sentence contains a contrasting statement featuring another subject. For example:

Io non lo so ma lui lo sa benissimo.

I don’t know but he knows very well.


A closely related phrase to non lo so is non saprei, literally translating as I wouldn’t know.

Whereas the former is a more definite response, the latter expresses some uncertainty because you don’t feel you have enough knowledge or experience to respond with conviction. It is often used when you sincerely want to give a useful response but are unable.

Comparing the two examples below should give you a better idea of how the nuance of these two phrases differs:

A: Come funziona questa macchina? (How does this car work?)
B: Non lo so. (I don’t know.)
Person B has no interest in helping or continuing the conversation.


A: Come funziona questa macchina? (How does this car work?)
B: Mmm, non saprei. Non mi intendo di macchine… (Hmm, I don’t know. Cars aren’t my expertise…)
Person B would like to help but doesn’t have the knowledge.

Another useful expression is non ho la minima idea (I have no idea or I absolutely have no idea). Although it can work as a standalone answer, it is also used at a beginning of a sentence to state that you don’t know how to solve a problem or face a situation.

Non ho la minima idea di chi sia quel signore lì.

I have no idea who that gentleman is.


If you are nervous or annoyed, you could say che ne so io? which means why or how should I know. It is not the nicest way to answer a question however.

Chi ha preso le mie chiavi? – E che ne so io?!

Who took my keys? – How should I know?!


Trivia: A fun one-word expression in Italian is boh! It means that you don’t know, or you’re not sure.

Sai a che ora passa il pullman oggi? – Boh!

Do you know what time the bus comes today? – Boh!


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