U dnevnom boravku je nova fotelja pokraj radijatora.

Because u can take different cases depending on meaning.

• u + locative = location, when something is somewhere
• u + accusative = motion, when something goes into somewhere

Here the sentence describes where the armchair is, so Croatian uses the locative:

• dnevni boravak = living room
• u dnevnom boravku = in the living room

So dnevnom boravku is the locative singular form.

Because both the adjective and the noun must match the locative singular.

The base form is:

• dnevni boravak = living room

In the locative singular, it becomes:

• dnevnom boravku

Breakdown:

• dnevni → dnevnom
• boravak → boravku

This is normal adjective-noun agreement in Croatian: the adjective changes together with the noun.

Because fotelja is a feminine singular noun, and the adjective must agree with it.

• fotelja = armchair
• nov = new

Agreement gives:

• masculine: nov
• feminine: nova
• neuter: novo

So:

• nova fotelja = a new armchair / the new armchair

Both words are in the nominative singular, because fotelja is the subject of the sentence.

Because pokraj is a preposition that normally takes the genitive case.

The base form is:

• radijator = radiator

After pokraj, it becomes:

• pokraj radijatora = beside the radiator

So radijatora is the genitive singular form.

Pokraj uses the genitive.

So in this sentence:

• pokraj radijatora

you get:

• radijator → radijatora

Other prepositions that often use the genitive include bez, kod, do, od, and iz.

Because je is a clitic form of biti in the present tense, and clitics usually go in the second position in the sentence.

So Croatian often places je after the first phrase or unit, not necessarily after the subject.

Here the first unit is:

• U dnevnom boravku

Then comes the clitic:

• je

So the sentence is:

• U dnevnom boravku je nova fotelja pokraj radijatora.

This word order is very natural in Croatian.

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

For example, you could also say:

• Nova fotelja je u dnevnom boravku pokraj radijatora.

That is also grammatical. The difference is mainly about focus or style.

• U dnevnom boravku je... puts the location first
• Nova fotelja je... puts the armchair first

In the original sentence, the speaker is probably emphasizing where the armchair is.

Because Croatian does not have articles like English.

So nova fotelja can mean:

• a new armchair
• the new armchair

Which one is intended depends on context.

This is very normal in Croatian, and learners usually have to get used to understanding definiteness from the situation rather than from a separate word.

Yes, in standard Croatian it is necessary.

Je is the 3rd person singular present form of biti = to be.

Since the sentence means something like There is / is located a new armchair..., Croatian uses je.

Without je, the sentence would sound incomplete in normal standard usage.

Not necessarily. Pokraj usually means beside, next to, or by.

It tells you that the armchair is near the radiator, but it does not automatically mean physical contact. The exact distance depends on context.

In everyday use, pokraj is close in meaning to pored, and in many situations they can be translated similarly.

The subject is nova fotelja.

You can tell because:

• it is in the nominative
• the verb je is singular
• fotelja is singular, so the verb matches it

The other parts are location phrases:

• u dnevnom boravku = in the living room
• pokraj radijatora = beside the radiator

So the basic structure is:

• location + je
  • subject + additional location phrase