Otkud to znaš?

In this sentence, otkud means something like how come, where did you get the idea, or literally from where.

It is often used when you are surprised that someone knows something. So it is not only about physical origin; it can also ask about the source of someone's knowledge.

Both can relate to from where, but otkud often sounds more conversational and more expressive, especially in questions like this one.

• Otkud to znaš? = How do you know that? / How come you know that?
• Odakle to znaš? also works and is very common, but it can sound a little more neutral or literal: From where do you know that?

In many everyday situations, they overlap, but otkud often carries more surprise.

Here to means that.

So Otkud to znaš? is literally something like How do you know that?

This to refers to some fact, information, or statement already mentioned or understood from context.

Because in Serbian, the natural place for to in this kind of sentence is before the verb.

• Natural: Otkud to znaš?
• Unnatural or much less likely: Otkud znaš to?

With verbs like znati, Serbian often puts the object pronoun-like element before the verb in short, natural questions. English speakers often expect a more English-like order, but Serbian does not work that way here.

Znaš is the 2nd person singular present tense of znati = to know.

So it means you know when speaking to one person informally.

The full pattern is:

• ja znam = I know
• ti znaš = you know
• on/ona/ono zna = he/she/it knows
• mi znamo = we know
• vi znate = you know / you all know
• oni/one/ona znaju = they know

Yes. Because znaš is the ti form, it is used when talking to one person informally: a friend, family member, child, classmate, and so on.

If you want to be polite or formal, use:

Otkud to znate?

That uses znate, the vi form.

Usually it sounds at least a little surprised. Depending on tone, it can mean:

• genuine curiosity: How do you know that?
• surprise: Wait, how do you know that?
• suspicion: How would you know that?

So the exact feeling depends a lot on intonation and context.

Yes, and it is very common.

There is a nuance:

• Kako to znaš? = How do you know that?
  This focuses more on how in the sense of by what method / in what way / through what reasoning.

• Otkud to znaš? = How come you know that? / Where did you get that information?
  This focuses more on the source of the knowledge and often sounds more surprised.

Both are natural, but they are not always exactly interchangeable.

It is written as one word: otkud.

Learners sometimes try to split it because they recognize od or other prepositions, but the standard written form here is a single word.

A simple pronunciation guide is:

OT-kood toh ZNASH

A few notes:

• u sounds like oo in food
• š sounds like sh in shoe
• znaš begins with zn-, and both consonants are pronounced

So do not turn z silent. It is really znaš, not naš.

Yes, very naturally.

For example, someone suddenly tells you a fact you did not expect them to know. You can respond with Otkud to znaš? to ask where they learned it or to show surprise that they know it at all.

That is one of the most typical uses of this sentence.

Sometimes, yes, but the meaning changes slightly.

• Otkud znaš? = How do you know?
• Otkud to znaš? = How do you know that?

Including to makes the question point more clearly to a specific piece of information.

Yes. It is a completely normal standalone question in conversation.

Like many short Serbian questions, it relies on context. The listener is expected to know what to refers to from the previous sentence or situation. That makes it very natural in real speech.