A szoba napfényes.

A is the definite article, so it means the.

Hungarian has two forms of the definite article:

• a before a consonant sound
• az before a vowel sound

Since szoba begins with sz, which is a consonant sound, the correct form is a:

• a szoba = the room
• but az ablak = the window

In Hungarian, the verb to be is usually left out in the present tense, third person when the predicate is a noun or an adjective.

So:

• A szoba napfényes. = The room is sunny.

But with other persons, Hungarian does use forms of to be:

• Én fáradt vagyok. = I am tired.
• Te fáradt vagy. = You are tired.

And in other tenses, the verb also appears.

Because here napfényes is not directly describing the noun inside a noun phrase; it is the predicate of the sentence.

Compare:

• A szoba napfényes. = The room is sunny.
• A napfényes szoba = the sunny room

So:

• noun + adjective can mean The noun is adjective
• article + adjective + noun means the adjective noun

This is a very important difference in Hungarian.

Napfényes comes from:

• napfény = sunlight
• -es = an adjective-forming suffix, often meaning having, full of, or characterized by

So napfényes literally means something like:

• sunlit
• full of sunlight
• bright with sunlight

In natural English, it is often translated as sunny depending on context.

Yes, often you can.

There is a slight nuance:

• napos = sunny, receiving a lot of sun
• napfényes = sunlit, bright with sunlight

In many everyday contexts, both can describe a bright room.
But napfényes can sound a bit more like filled with sunlight, while napos is the more general sunny.

Hungarian spelling is fairly regular, so pronunciation is predictable.

Useful parts here:

• sz sounds like English s in see
• ny sounds like the ny sound in canyon
• é is a long vowel, roughly like ay in say, but steadier

Approximate pronunciations:

• szoba ≈ SO-baw
• napfényes ≈ NAHP-fay-nyesh

Also note: Hungarian stress is usually on the first syllable, so:

• SZO-ba
• NAP-fé-nyes

Because it is the subject of the sentence, and Hungarian subjects are normally in the basic form of the noun, called the nominative.

So:

• szoba = room / the room in basic form

Other endings appear when the noun has another role:

• szobát = the room as a direct object
• szobában = in the room
• szobából = out of the room

But in A szoba napfényes, szoba is just the subject, so no extra ending is needed.

Yes, that is grammatical.

Hungarian word order is flexible and often shows focus or emphasis rather than just grammatical relationships.

• A szoba napfényes. = neutral statement: The room is sunny.
• Napfényes a szoba. = stronger focus on sunny, something like The room is sunny / It’s sunny, the room is

So both are correct, but the emphasis is different.

No. Hungarian does not have grammatical gender like many European languages do.

So:

• szoba is not masculine, feminine, or neuter
• napfényes does not change for gender
• there is no difference like sunny vs sunny for masculine/feminine forms

This makes Hungarian simpler in that respect than languages such as German, French, or Spanish.

Yes, in this kind of sentence it does.

Compare:

• A szoba napfényes. = The room is sunny.
• A szobák napfényesek. = The rooms are sunny.

So in a predicate position, the adjective becomes plural too.

But when the adjective is placed before the noun as a simple modifier, it usually does not take a plural ending:

• a napfényes szoba = the sunny room
• a napfényes szobák = the sunny rooms

That difference is very common in Hungarian.