On és el teu passaport?

On means where.

It is the normal Catalan question word used to ask about location:

• On és...? = Where is ...?
• On vius? = Where do you live?

So in this sentence, On introduces the location question.

Catalan normally puts the question word first, just like English often does:

• On és el teu passaport? = Where is your passport?

So the basic order is:

• On
  • verb
    • subject

This is very natural in Catalan.
A form like És on... would not be the normal way to ask this question.

És is the he/she/it is form of the verb ser.

Here it means is:

• On és el teu passaport? = Where is your passport?

The accent is important because:

• és = is
• es = an unstressed pronoun, often like oneself / itself / each other, depending on context

So the accent helps distinguish two different words.

This is a very common learner question.

In Catalan, location is often expressed with ser, especially when asking where something is:

• On és el teu passaport?

In many everyday situations, this is the most normal choice.

You may also hear estar in some contexts or varieties, but for a basic learner sentence, On és...? is standard and very common.

A useful beginner rule is:

• for Where is ...?, On és...? is usually a safe choice

Because Catalan usually uses the definite article with a possessive adjective.

So where English says:

• your passport

Catalan often says literally:

• the your passport → el teu passaport

This is normal Catalan grammar:

• el meu llibre = my book
• la teva bossa = your bag
• els seus amics = his/her/their friends

So el teu passaport is the expected form.

Teu means your, but specifically the form used with a masculine singular noun.

Since passaport is masculine singular, Catalan uses teu:

• el teu passaport = your passport

Related forms are:

• teu = your, masculine singular
• teva = your, feminine singular
• teus = your, masculine plural
• teves = your, feminine plural

For example:

• la teva maleta = your suitcase
• els teus documents = your documents
• les teves claus = your keys

You can tell here because it uses the masculine article el:

• el passaport

That means the noun is masculine singular.

As a result, the possessive must match it:

• el teu passaport

If the noun were feminine, the article and possessive would change too.

In standard Catalan, that would normally sound wrong.

With a possessive like teu, Catalan usually keeps the article:

• On és el teu passaport? ✅

not normally:

• On és teu passaport? ❌

So for most everyday learner use, remember:

• article + possessive + noun
• el teu passaport
• la meva bossa
• els nostres llibres

Yes. Teu is the informal singular your, used when speaking to one person you address as tu.

So this sentence is talking to one person informally:

• On és el teu passaport?

If you wanted a more formal version, you would usually use seu/seva with vostè:

• On és el seu passaport? = Where is your passport? (formal)

This can also mean his/her passport, so context matters.

A simple learner-friendly pronunciation guide is:

• On ≈ ohn
• és ≈ ess
• el ≈ el
• teu ≈ roughly teh-oo said smoothly, almost like one syllable in fast speech
• passaport ≈ pah-suh-PORT

Very roughly as a whole:

• ohn ess el teh-oo pah-suh-PORT?

A few notes:

• és has a clear e sound
• teu contains a diphthong, so the vowels run together
• passaport is stressed on the last syllable: -port

No. Unlike English, Catalan does not need a helper like do.

Compare:

• English: Where is your passport?
• Catalan: On és el teu passaport?

Catalan forms this kind of question simply with:

• the question word (On)
• the verb (és)
• the subject phrase (el teu passaport)

So there is no equivalent of English do/does here.

Yes, you might hear that, especially for emphasis or in conversation:

• El teu passaport, on és?

This feels a bit more like:

• Your passport, where is it?

But the most neutral and straightforward version is:

• On és el teu passaport?

That is the form learners should probably use first.

A very useful pattern is:

• On és el/la teu/teva ... ? = Where is your ... ?

Examples:

• On és la teva bossa? = Where is your bag?
• On és el teu telèfon? = Where is your phone?
• On són els teus documents? = Where are your documents?

You can also generalize it further:

• On és el meu llibre? = Where is my book?
• On és la clau? = Where is the key?
• On són les claus? = Where are the keys?

So this sentence is a very useful model for asking about location.