A károsanyag-kibocsátás alacsony.

Because in Hungarian, the verb van (to be) is usually left out in the present tense, 3rd person when the predicate is a noun or adjective.

So:

• A károsanyag-kibocsátás alacsony. = The pollutant emission is low.

Hungarian does not normally say A károsanyag-kibocsátás van alacsony here.

But the verb appears in other persons or tenses, for example:

• Alacsony volt. = It was low.
• Alacsony lesz. = It will be low.

It is a compound noun made from smaller parts:

• káros = harmful
• anyag = material, substance
• káros anyag / károsanyag = harmful substance, pollutant
• kibocsátás = emission, releasing

So károsanyag-kibocsátás literally means something like pollutant emission or emission of harmful substances.

Hungarian often packs ideas into long compound words where English would use several separate words.

Because this is a long compound word.

In Hungarian, compounds are often written as one word, but if a compound has:

• more than two elements, and
• more than six syllables

then a hyphen is often used to make it easier to read.

Here the parts are basically:

• káros
• anyag
• kibocsátás

So the hyphen helps show the structure of the compound.

Hungarian has two forms of the definite article:

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

Since károsanyag-kibocsátás starts with k, which is a consonant, the correct form is a:

• a károsanyag-kibocsátás

If the next word began with a vowel, you would use az instead.

Hungarian often uses the definite article when talking about something as a general concept or known category.

So A károsanyag-kibocsátás alacsony can mean something like:

• The pollutant emission is low
• Pollutant emission is low

This is similar to other general statements in Hungarian, for example:

• A dohányzás káros. = Smoking is harmful.

Leaving out the article here would usually sound unnatural.

Usually no, not in the normal generic meaning.

• a = the
• egy = a/an, one

Here a is used because the sentence is talking about the concept/category of pollutant emission, or a contextually understood emission level.

If you said egy károsanyag-kibocsátás, that would suggest one emission or a particular emission event, which is not the usual meaning here.

It is the subject of the sentence.

Its form is the basic dictionary form, with no case ending, so it is in the nominative.

Structure:

• A károsanyag-kibocsátás = the subject
• alacsony = the predicate adjective

So the sentence is literally structured as:

• The pollutant emission — low.

with the verb is understood.

Here alacsony is a predicate adjective meaning low.

With a singular subject, it stays singular:

• A károsanyag-kibocsátás alacsony.

If the subject were plural, the predicate adjective would normally also show plural:

• A károsanyag-kibocsátások alacsonyak. = The pollutant emissions are low.

So in this sentence, alacsony is singular because the subject is singular.

Also, Hungarian adjectives do not change for gender, because Hungarian has no grammatical gender.

Yes.

The given sentence is the neutral order:

• A károsanyag-kibocsátás alacsony.

This presents the pollutant emission as the topic, and low as the new information.

You could also say:

• Alacsony a károsanyag-kibocsátás.

That version puts more emphasis on alacsony. In English, it can feel like:

• The pollutant emission is low.
• It is low, the pollutant emission.

Both are grammatical, but the emphasis is different.

A rough pronunciation guide is:

• KAA-rosh-ah-nyag kee-bo-CHAA-taash

A few useful sound notes:

• á is a long vowel
• s sounds like English sh
• cs sounds like English ch
• ny sounds like the ny in canyon or like Spanish ñ

Also, Hungarian stress normally falls on the first syllable of the word:

• KÁrosanyag-kibocsátás
• Alacsony