A gyerek zoknit kér, mert hideg van a szobában.

A is the definite article, like the in English. So a gyerek means the child.

In a simple sentence like this, Hungarian normally uses the article if the noun is definite. You can leave articles out in some special expressions, but gyerek by itself would not be the normal neutral choice here.

Because zoknit is being used as an indefinite, nonspecific object.

Hungarian often allows a bare noun here:

• zoknit kér = asks for sock(s), asks for a sock, asks for socks as an item of clothing
• egy zoknit kér = asks for one sock
• a zoknit kéri = asks for the specific sock

So the lack of article helps show that the object is not definite.

The -t marks the direct object. It is the Hungarian accusative ending.

So:

• zokni = sock
• zoknit = sock as the thing being asked for

Since kér takes a direct object, that object usually gets the accusative ending.

Hungarian verbs have two main conjugations: indefinite and definite.

Here the object is indefinite: zoknit. So the verb is in the indefinite form:

• kér = asks for

If the object were definite, you would usually use the definite form:

• A gyerek a zoknit kéri. = The child is asking for the sock.

So the important thing is not that there is an object, but whether that object is definite or indefinite.

Grammatically, zoknit is singular. But in real usage, Hungarian often uses the singular for clothing items in places where English may prefer a plural.

So zoknit kér can naturally be translated as asks for socks in context.

If you wanted to make the plural explicit, you could say:

• zoknikat kér = asks for socks

But the singular is very normal here.

Because hideg van is the normal Hungarian way to say that the temperature is cold.

Literally, it is something like there is cold rather than it is cold. This is just how Hungarian expresses this idea idiomatically.

Also compare:

• Hideg van. = It is cold.
• A szoba hideg. = The room is cold.

In A szoba hideg, there is a real subject (the room), so Hungarian does not use van in the present tense with the adjective. But in the general temperature expression hideg van, van is used.

Because Hungarian does not use a dummy subject like English it in expressions such as:

• it is cold
• it is raining
• it is late

Hungarian simply says:

• Hideg van.
• Esik.
• Késő van.

So the English it has no separate word here.

A szobában means in the room.

It breaks down like this:

• a = the
• szoba = room
• -ban / -ben = in

So:

• szobában = in a room / in the room, depending on context
• a szobában = in the room

The ending is -ban because szoba has back vowels, and Hungarian suffixes follow vowel harmony.

Also, the final a in szoba becomes long before the suffix:

• szoba → szobában

Yes, a szobában hideg van is also correct.

Hungarian word order is flexible, but the order helps show what is the topic or what is being emphasized.

• hideg van a szobában = neutral here, with the fact of coldness coming first
• a szobában hideg van = puts in the room first, as the setting or topic

Both are natural. The sentence you have is perfectly normal.

Mert means because.

A useful thing for English speakers to know is that Hungarian does not send the verb to the end of the clause after mert the way German does after weil.

So Hungarian keeps a fairly normal clause structure:

• mert hideg van a szobában

That is completely standard.

Yes. Gyerek is a very common everyday word for child/kid.

You may also see gyermek, which also means child, but that sounds more formal, careful, or literary.

So in an ordinary sentence like this, gyerek is the natural choice.