Nem elég, hogy késik a szertartás, a násznép még késik is.

Literally, nem elég means it is not enough, but in this pattern it is an idiomatic complaint.

Nem elég, hogy ... means something like:

• It’s bad enough that ...
• As if it weren’t enough that ...
• Not only is it the case that ..., but ...

So the sentence has a frustrated, complaining tone.

Here hogy means that and introduces a full clause:

• Nem elég, hogy késik a szertartás
  = It’s bad enough that the ceremony is late

This is a very common Hungarian structure:
Nem elég, hogy + clause, ...

So hogy is not optional here in standard usage; it links nem elég to the following statement.

It can cover both ideas, depending on the subject.

• késik a szertartás = the ceremony is delayed / is starting late
• késik a násznép = the wedding party is late

So Hungarian uses the same verb, késik, where English may choose different expressions.

Because there are two separate things being said:

1. a szertartás késik = the ceremony is late/delayed
2. a násznép késik = the wedding party is late

Hungarian normally repeats the verb instead of leaving it understood. English might sometimes avoid repetition, but in Hungarian this is completely natural.

In this sentence, még ... is adds the idea of on top of that, even, or to make matters worse.

So:

• a násznép még késik is

means roughly:

• the wedding party is late too
• the wedding party is even late
• to make matters worse, the wedding party is also late

Here még is not just simple still. Together with is, it gives extra emphasis and annoyance.

Both are possible, but they emphasize different things.

• a násznép is késik
  = the wedding party is late too
  This is a more straightforward too/also.

• a násznép még késik is
  = the wedding party is even late / is late as well, on top of everything
  This sounds more emphatic and fits the complaining tone after Nem elég, hogy ...

The position of is matters. Hungarian is usually follows the word or phrase it connects to. Here it follows the verb phrase, so the extra emphasis falls on the fact of being late.

Násznép means the group of people connected with the wedding, especially the wedding party or wedding guests as a collective.

It is a collective noun: it refers to many people, but grammatically it behaves as singular.

That is why the verb is singular:

• a násznép késik
  not a násznép késnek

This is similar to how some English collective nouns can act as singular, though Hungarian is more consistent about it here.

Because both are definite:

• a szertartás = the ceremony
• a násznép = the wedding party / the wedding guests

In context, these are specific, identifiable things, not just a ceremony or some wedding guests.

Hungarian uses a / az as the definite article, like the in English.
Here a is used because the next word begins with a consonant.

Yes, especially in the second clause.

The neutral order would be something like:

• A szertartás késik.
• A násznép is késik.

But the actual sentence is more expressive:

• Nem elég, hogy késik a szertartás, a násznép még késik is.

A few things are happening:

1. In késik a szertartás, the verb comes first. This is fine in Hungarian and can sound slightly more dynamic or presentational.
2. In a násznép még késik is, the placement of még and is creates emphasis on the predicate being late.
3. The whole sentence is built for rhetorical complaint, not neutral description.

So the word order is not random; it helps create the annoyed tone.

People really do use this pattern, especially when complaining or sounding dramatic:

• Nem elég, hogy ..., még ... is.

It is not overly formal, but it is definitely expressive. It sounds stronger than a plain factual statement.

So this sentence does not just report two delays; it conveys irritation:

• first the ceremony is delayed,
• and then, as if that were not enough, the wedding party is late too.