A szelektív hulladékgyűjtés nagyon fontos.

It means Selective waste collection is very important.

Depending on context, a more natural English translation might also be Recycling is very important, although the Hungarian is more literally about separating and collecting waste selectively.

A is the Hungarian definite article, meaning the.

So A szelektív hulladékgyűjtés literally means the selective waste collection.

In Hungarian, the definite article is often used in places where English may or may not use the, so it is very normal here.

In Hungarian, in the present tense, third person singular, the verb to be is usually left out.

So:

• A szelektív hulladékgyűjtés nagyon fontos. = Selective waste collection is very important.

Hungarian does not need a separate word for is here.

But in other persons, the verb does appear:

• Fontos vagyok = I am important
• Fontos vagy = you are important
• Fontos = he/she/it is important

Szelektív means selective.

Here it is an adjective describing hulladékgyűjtés.

It does not change form for gender or number, because Hungarian adjectives do not agree with nouns the way they do in many Indo-European languages. So the adjective stays the same:

• szelektív gyűjtés = selective collection
• szelektív módszer = selective method
• szelektív rendszerek = selective systems

Hulladékgyűjtés is a compound noun:

• hulladék = waste
• gyűjtés = collection, collecting

So hulladékgyűjtés literally means waste collection.

Hungarian very often forms long compound words like this, and learners should get used to seeing several ideas packed into one word.

You should think of it as one noun phrase:

• szelektív = selective
• hulladékgyűjtés = waste collection

Together:

• szelektív hulladékgyűjtés = selective waste collection

So the structure is:

• A = the
• szelektív hulladékgyűjtés = selective waste collection
• nagyon fontos = very important

Nagyon means very.

It modifies the adjective fontos:

• fontos = important
• nagyon fontos = very important

This is a very common pattern in Hungarian:

• nagyon jó = very good
• nagyon nehéz = very difficult
• nagyon érdekes = very interesting

The neutral word order here is very natural:

• A szelektív hulladékgyűjtés nagyon fontos.

This presents the topic first, then says something about it: Selective waste collection is very important.

Hungarian word order is flexible, but changes often affect emphasis. For example:

• Nagyon fontos a szelektív hulladékgyűjtés.

This is also correct, but it puts more focus on very important.

So both are possible, but the original sentence is a straightforward, neutral way to say it.

Fontos is an adjective, meaning important.

After a subject like A szelektív hulladékgyűjtés, Hungarian uses the adjective directly:

• A könyv érdekes. = The book is interesting.
• Ez nehéz. = This is difficult.
• A szelektív hulladékgyűjtés fontos. = Selective waste collection is important.

Fontosan would be an adverb-like form, something like importantly, which would not fit here.

A rough pronunciation guide is:

hool-lah-dayk-dyooy-taysh

A few useful points:

• hu in hulladék has a short u
• é is a long vowel, roughly like ay in say
• gy is a special Hungarian consonant, somewhat like a very soft dy
• ű is a long front rounded vowel; English does not really have it, so learners often approximate it
• és at the end sounds like aysh

You do not need perfect pronunciation immediately, but it helps to notice that Hungarian spelling is quite regular.

Yes, in many everyday contexts that is a natural English translation.

But strictly speaking, szelektív hulladékgyűjtés is closer to:

• selective waste collection
• separate waste collection
• sorting waste for collection

English often uses recycling more broadly, so whether that translation is best depends on context.

It is singular.

The subject is A szelektív hulladékgyűjtés, which is one abstract activity or concept: selective waste collection.

That is why the predicate adjective is just fontos with no plural marking.

If you were talking about multiple things being important, Hungarian could mark plural on the noun, but here the whole idea is treated as a single concept.