Nazivni kapacitet je velik.

Croatian does not have articles, so there is no separate word for the or a/an.

So Nazivni kapacitet je velik can mean The rated capacity is large or A rated capacity is large, depending on context. In real use, context usually makes it clear which meaning is intended.

Je is the 3rd person singular present tense of biti (to be), so it means is.

It links the subject nazivni kapacitet with the description velik:

• Nazivni kapacitet = the subject
• je = is
• velik = the description

It is in the nominative singular, because it is the subject of the sentence.

• kapacitet is a masculine singular noun
• nazivni agrees with it, so it is also masculine singular nominative

This is the basic dictionary form of both words.

In Croatian, many nouns ending in a consonant are masculine, and kapacitet follows that pattern.

Because it is masculine singular, the adjectives around it also appear in masculine singular forms:

• nazivni kapacitet
• kapacitet je velik

This is one of the most common noun patterns in Croatian.

This is a very common learner question.

With some masculine singular adjectives, Croatian has a short form and a long form in the nominative:

• velik = short form
• veliki = long form

After je, when the adjective is used as a predicate, Croatian usually prefers the short form:

• Kapacitet je velik.

Before a noun, the long form is very common:

• veliki kapacitet

So in this sentence, velik sounds natural and standard.

Because not all adjectives behave like velik.

Nazivni is a different type of adjective, often called a relational adjective, and it normally appears only in this form. So nazivni kapacitet is the standard expression.

In other words, the short/long contrast is relevant for adjectives like velik, but not for every adjective in Croatian.

Yes.

In Croatian, adjectives agree with the noun they describe in gender, number, and case.

So here:

• nazivni agrees with kapacitet
• velik also agrees with kapacitet, even though it comes after je

That is why both are masculine singular.

For comparison:

• Nazivna snaga je velika.
  feminine singular

• Nazivni kapaciteti su veliki.
  masculine plural

Yes, Croatian word order is fairly flexible, but some orders are more neutral than others.

Nazivni kapacitet je velik is a normal, neutral sentence.

You could also hear:

• Kapacitet je velik.
  if nazivni is understood or not important

A more unusual order like Velik je nazivni kapacitet is possible, but it sounds marked, emphatic, or stylistically special.

Normally, no.

In a standard full sentence, je is needed:

• Nazivni kapacitet je velik.

Leaving it out would sound incomplete in normal prose or speech. You might see the verb omitted in headlines, notes, or very compressed styles, but not in ordinary standard sentences like this one.

Yes.

Here velik is a predicate adjective, and it agrees with the subject kapacitet. Because the subject is masculine singular nominative, velik is also masculine singular nominative.

So even after je, the adjective still matches the subject.

You replace je with nije:

• Nazivni kapacitet nije velik.

That means The rated capacity is not large.

This is a very common pattern in Croatian:

• je = is
• nije = is not

A standard way is:

• Je li nazivni kapacitet velik?

This means Is the rated capacity large?

In conversation, intonation can also signal a question, but Je li ... ? is the clearest standard pattern for learners to use.