Hvala vam na usluzi.

Yes, but they do different jobs:

• vam = to you / to you all / polite to you
• na usluzi = for the service / favor

So the structure is basically:

• Hvala = Thanks
• vam = to you
• na usluzi = for the service/favor

In natural English, we usually just say Thank you for the service/favor, but Croatian can show both:

• who is being thanked → vam
• what they are being thanked for → na usluzi

Vam is the dative form of vi.

It can mean:

• to you when speaking politely to one person
• to you all when speaking to more than one person

So in this sentence, vam is either:

• polite singular, or
• plural

That makes the sentence sound polite or respectful.

Compare:

• Hvala ti na usluzi. = thanks to you (informal, singular)
• Hvala vam na usluzi. = thanks to you (formal singular or plural)

Because after na in this expression, Croatian uses the locative case.

The dictionary form is:

• usluga = service, favor

But after na, it becomes:

• na usluzi

So:

• usluga = base form
• usluzi = locative singular form

This is a very common pattern after certain prepositions.

In Croatian, hvala na ... is the normal pattern for saying thanks for ...

So you often get:

• Hvala na pomoći. = Thanks for the help.
• Hvala na odgovoru. = Thanks for the answer.
• Hvala na usluzi. = Thanks for the service/favor.

You should learn hvala na + locative as a common chunk.

Croatian also allows just:

• Hvala vam. = Thank you.

And then you can add na ... if you want to say what you are thanking someone for.

Usluga can mean a few related things, depending on context:

• service in a general sense
• favor
• helpful act
• courtesy

In Hvala vam na usluzi, it often feels like:

• Thank you for the favor or
• Thank you for your service/help

The exact English translation depends on the situation.

If someone did something personally helpful for you, favor may fit best. If you are speaking more formally, service may fit better.

Yes, it is at least somewhat formal or polite.

The main reason is vam, which is:

• formal singular, or
• plural

Also, usluga can sound a bit more formal or deliberate than a very simple pomoć (help) in some contexts.

So Hvala vam na usluzi. is polite and perfectly correct, but in everyday speech people might also simply say:

• Hvala.
• Hvala vam.
• Hvala na pomoći.

The best choice depends on the situation.

Yes. That would be the informal singular version.

• Hvala ti na usluzi. = Thanks for the favor/service.
  You are speaking to one person informally.

• Hvala vam na usluzi. = Thanks for the favor/service.
  You are speaking politely to one person, or to more than one person.

So the difference is mainly in ti vs vam:

• ti = informal singular
• vam = formal singular or plural

Yes, absolutely.

• Hvala na usluzi. = Thanks for the favor/service.
• Hvala vam na usluzi. = Thank you for the favor/service.

Including vam makes it more explicit who you are thanking and often sounds a bit warmer or more polite.

Both are correct.

The most neutral order is:

• Hvala vam na usluzi.

But Croatian word order is more flexible than English, so other versions are possible in context, such as:

• Hvala na usluzi.
• Na usluzi vam hvala. — possible, but marked and not the normal learner version
• Vam hvala na usluzi. — also marked

As a learner, the safest choice is to keep:

• Hvala vam na usluzi.

A simple learner-friendly pronunciation guide is:

• Hvala ≈ HVAH-lah
• vam ≈ vahm
• na ≈ nah
• usluzi ≈ oo-SLOO-zee

A rough full pronunciation:

• HVAH-lah vahm nah oo-SLOO-zee

A few useful sound notes:

• h is pronounced, unlike in many English words
• v is a normal v
• u is like oo in food
• z is like English z

Yes, but the exact context matters.

It works well when:

• someone has done you a favor
• someone has helped you with something
• you want to sound polite and appreciative

It may sound especially natural in:

• somewhat formal interactions
• written communication
• polite spoken thanks

In very casual daily speech, many people would simply say:

• Hvala.
• Hvala vam.
• Puno hvala.
• Hvala na pomoći.

So Hvala vam na usluzi. is correct and natural, but it is a bit more specific than plain Hvala.

Yes.

Hvala alone already means:

• Thanks or
• Thank you

Everything else in Hvala vam na usluzi adds extra information:

• vam = to you
• na usluzi = for the favor/service

So you can build up from the shortest form:

• Hvala.
• Hvala vam.
• Hvala na usluzi.
• Hvala vam na usluzi.

Yes. Depending on tone and context, you might also hear:

• Hvala vam. = Thank you.
• Puno vam hvala. = Thank you very much.
• Hvala lijepa. = Thank you kindly / many thanks.
• Hvala na pomoći. = Thanks for the help.
• Zahvaljujem vam na usluzi. = I thank you for the favor/service.
  This is more formal.

So Hvala vam na usluzi. is one good polite option, but not the only one.

A very useful pattern is:

• Hvala + dative + na + locative

Using this sentence:

• Hvala = thanks
• vam = dative
• na usluzi = na
  • locative

You can reuse the pattern in many sentences:

• Hvala vam na pomoći. = Thank you for the help.
• Hvala vam na odgovoru. = Thank you for the answer.
• Hvala vam na vremenu. = Thank you for your time.

This makes the sentence a great model to learn from.