Stavi bijelu vrpcu na poklon, molim te.

Stavi is the imperative form of the verb staviti, meaning put, place, or attach.

In this sentence, it is a command addressed to one person informally:

• stavi = put! / place!

So the speaker is telling someone directly to do the action.

This is about aspect, which is very important in Croatian.

• staviti = perfective
  It focuses on a single completed action
• stavljati = imperfective
  It suggests a repeated, ongoing, or habitual action

In a sentence like this, where someone is asking for one complete action, Croatian normally uses the perfective imperative:

• Stavi bijelu vrpcu... = put the ribbon on

If you used stavljaj, it would sound more like:

• keep putting it on
• put it on repeatedly
• be in the process of putting it on

So stavi is the natural choice here.

Because bijelu vrpcu is the direct object of the verb, so it must be in the accusative case.

The dictionary forms are:

• bijela = white
• vrpca = ribbon

But in the accusative singular feminine, they become:

• bijelu
• vrpcu

So:

• bijela vrpca = a white ribbon, as the subject
• stavi bijelu vrpcu = put a white ribbon, as the object

The adjective and noun must agree in:

• gender
• number
• case

Here poklon is in the accusative singular.

The preposition na can take different cases depending on meaning:

• accusative = movement toward a place or placing something onto something
• locative = location, being on something

In this sentence, the meaning is put the ribbon onto the gift, so Croatian uses na + accusative:

• na poklon

Because poklon is a masculine inanimate noun, its accusative singular looks the same as the nominative:

• nominative: poklon
• accusative: poklon

This is the same na + accusative / locative contrast.

• na poklon = onto the gift, put it on the gift
• na poklonu = on the gift, located on the gift

So:

• Stavi vrpcu na poklon. = Put the ribbon onto the gift.
• Vrpca je na poklonu. = The ribbon is on the gift.

The first expresses direction/result of placement.
The second expresses location.

Vrpca usually means ribbon.

Depending on context, it can also refer to a strip or band of material, but in a sentence with a gift, ribbon is clearly the intended meaning.

So bijela vrpca is simply a white ribbon.

Molim te means please when speaking to one person informally.

Literally, it is connected to the verb moliti, and its literal sense is something like I ask you, but in everyday speech it functions as a polite softener:

• Stavi bijelu vrpcu na poklon. = Put the white ribbon on the gift.
• Stavi bijelu vrpcu na poklon, molim te. = Please put the white ribbon on the gift.

It makes the command sound more polite and less abrupt.

Yes, it can go in different places.

At the end is very natural:

• Stavi bijelu vrpcu na poklon, molim te.

But you could also say:

• Molim te, stavi bijelu vrpcu na poklon.

Both are normal. The difference is mainly one of rhythm and emphasis, not core meaning.

Because Croatian does not have articles like English.

So vrpcu can mean:

• a ribbon
• the ribbon

And poklon can mean:

• a gift
• the gift

The exact meaning depends on context.

That is why English speakers often feel something is missing, but in Croatian this is completely normal.

Croatian usually leaves out subject pronouns when they are already clear from the verb form.

Here, stavi already tells you the command is aimed at you singular informal, so ti is unnecessary.

• Stavi bijelu vrpcu... = normal
• Ti stavi bijelu vrpcu... = possible, but adds emphasis or contrast

So if you include ti, it can sound like:

• you put it, not someone else

Yes. Croatian word order is fairly flexible, although some orders sound more neutral than others.

The given sentence is very natural:

• Stavi bijelu vrpcu na poklon, molim te.

You could also say:

• Na poklon stavi bijelu vrpcu, molim te.

That puts more emphasis on where the ribbon should go.

So the basic meaning stays the same, but changing word order can shift emphasis.

You would use the plural/formal imperative stavite and usually molim vas.

• Stavite bijelu vrpcu na poklon, molim vas.

This can mean:

• speaking politely to one person
• speaking to several people

So the contrast is:

• stavi / molim te = singular informal
• stavite / molim vas = plural or formal