Lončarsko kolo radi polako.

Because it agrees with kolo, which is a neuter singular noun.

In Croatian, adjectives change their endings to match the noun’s:

• gender
• number
• case

Here:

• kolo = neuter singular
• so the adjective is lončarsko = neuter singular nominative

That is why you get:

• lončarsko kolo = potter’s wheel

If the noun were masculine or feminine, the adjective would change:

• lončarski ... for masculine
• lončarska ... for feminine
• lončarsko ... for neuter

Radi is the 3rd person singular present tense of raditi.

So it can mean:

• works
• is working
• operates
• runs

In this sentence, radi means something like works / is operating.

Examples:

• Stroj radi. = The machine is working.
• Sat radi. = The clock works.
• Lončarsko kolo radi polako. = The potter’s wheel works slowly.

Croatian present tense often covers both English simple present and present continuous, depending on context.

It is an adverb.

Here it describes how the wheel works:

• radi polako = works slowly

That is why it does not change form.

Compare:

• polak / polagana / polagano = adjective-type forms, depending on the word and context
• polako = adverb = slowly

In this sentence, you need the adverb because it modifies the verb radi.

Because Croatian does not use articles like English the or a/an.

So:

• kolo can mean a wheel or the wheel
• the exact meaning depends on context

That means:

• Lončarsko kolo radi polako. could mean The potter’s wheel works slowly or A potter’s wheel works slowly, depending on the situation.

Croatian relies on context much more than English does for definiteness.

It is in the nominative singular.

Why? Because it is the subject of the sentence — the thing doing the action.

Breakdown:

• lončarsko kolo = subject
• radi = verb
• polako = adverb

So the basic structure is:

• [subject] [verb] [adverb]
• Lončarsko kolo radi polako.

Yes. Croatian word order is more flexible than English word order.

The most neutral order here is:

• Lončarsko kolo radi polako.

But other orders are possible, for example:

• Polako radi lončarsko kolo.
• Lončarsko kolo polako radi.

These alternatives may sound more marked and can change the emphasis slightly:

• putting polako earlier gives more focus to slowly
• putting the subject later can make it sound less neutral or more stylistic

So while Croatian allows more movement, the original sentence is the most straightforward and natural for a learner to start with.

Yes, here kolo means wheel.

But kolo is a word with several meanings in Croatian, depending on context. It can also refer to:

• a wheel
• a circle
• a traditional round dance
• sometimes a round in games or competitions

In lončarsko kolo, the context makes it clear that it means potter’s wheel.

Croatian often uses an adjective where English uses a noun plus -’s or of.

So:

• lončar = potter
• lončarski / lončarska / lončarsko = potter’s / pottery-related

Therefore:

• lončarsko kolo literally means something like potter-related wheel, which naturally becomes potter’s wheel in English

A phrase like kolo lončara would sound more like the wheel of the potter and is not the normal standard name for the object.

So lončarsko kolo is the standard, natural expression.

Not exactly.

Radi is pronounced roughly RAH-dee.

A few pronunciation points:

• r is rolled or tapped
• a is like a in father
• d is a clear d
• i is like ee in see

So radi is approximately:

• RAH-dee

Also, in Croatian spelling, words are usually pronounced very consistently, much more consistently than in English.

The letter č is pronounced like ch in chocolate, but usually with a firmer, harder sound.

So lončarsko is pronounced approximately:

• LON-char-sko

Very roughly:

• lon as in lawn without the w
• čar like char
• sko like sko

So the whole sentence is approximately:

• LON-char-sko KO-lo RAH-dee po-LAH-ko

Not in this sentence.

The verb raditi can sometimes be translated in broader ways depending on context, such as:

• to work
• to do work
• to operate

But if you want the very general English verb do, Croatian usually uses raditi only in certain contexts, not as a direct equivalent in every sentence.

Here, with a machine-like object such as lončarsko kolo, radi clearly means:

• works
• is working
• is operating

So does slowly would not be a good translation here.

Yes. It is a complete and natural sentence.

It has everything needed:

• a subject: lončarsko kolo
• a verb: radi
• an adverb: polako

It sounds like a normal statement meaning that the potter’s wheel is functioning slowly or turning slowly.

Depending on context, a Croatian speaker might also say something more specific, but this sentence is perfectly grammatical and natural.