Learn Hardcore Dutch: Het nachtelijk verkeer in de stad is vaak rustig. - Night traffic in the city is often quiet.

Nachtelijk is an adjective meaning “nightly” or “nocturnal.” Here it describes the time‐related characteristic of verkeer (traffic), so “nachtelijk verkeer” = “nightly traffic.”

Why isn’t there an -e on nachtelijk, even though it comes before the definite noun verkeer with het?

Dutch attributive adjectives generally take an -e when they precede a definite noun (e.g. het grote huis). However, time‐related adjectives like dagelijks, wekelijks or nachtelijk, when paired with mass/collective nouns, often remain uninflected in fixed expressions:

dagelijks leven (not ~dagelijkse leven~)
nachtelijk verkeer (not ~nachtelijke verkeer~)

This is simply a collocational exception: you treat nachtelijk verkeer as a set phrase.

What gender is verkeer, and why is het used instead of de?

Verkeer is a neuter noun in Dutch, so the definite article is het.

Common gender (de-words): most animate or concrete nouns → de man, de appel
Neuter (het-words): many abstract or collective nouns → het verkeer, het water

Why is in de stad placed after verkeer rather than at the very beginning of the sentence?

Dutch main clauses typically follow this order:
1) Subject (Het nachtelijk verkeer)
2) Finite verb (is)
3) Adverbials or PPs (in de stad, vaak)
4) Complement (rustig)

So in de stad is a locative prepositional phrase modifying verkeer and naturally comes after the subject–verb slot.

What does vaak mean, and why is it placed between is and rustig?

Vaak means “often.” In Dutch main clauses, frequency adverbs like vaak, soms, or altijd usually follow the finite verb:

Correct: De trein is vaak te laat.
Not: De trein vaak is te laat.

Here: Het verkeer is vaak rustig.

Why is rustig not inflected with -e?

Rustig is used predicatively (after the verb is), and predicative adjectives in Dutch never get an -e. Contrast:

Attributive: rustige straat (with -e)
Predicative: de straat is rustig (no -e)

Could you omit het and simply say Nachtelijk verkeer in de stad is vaak rustig?

No. In Dutch, definite singular nouns normally require an article. Without het, the sentence would be ungrammatical. You need het for verkeer here because you’re talking about the (specific) nightly traffic.

Can you rearrange the sentence to start with ’s nachts (“at night”)?

Yes. A natural alternative is:
’s Nachts is het verkeer in de stad vaak rustig.
Here ’s nachts is a time adverbial placed first, pushing the subject–verb into positions 2–3.

What’s the difference between nachtelijk verkeer and nachtverkeer?

nachtelijk verkeer: adjective + noun (“nightly traffic”)
nachtverkeer: compound noun (“night traffic”)

They mean almost the same, but nachtverkeer is a tighter compound and more common in headlines or technical contexts.

Could you use a synonym for rustig here?

Yes, depending on nuance:

kalm (calm) → is vaak kalm
stil (quiet, silence‐oriented) → is vaak stil

But rustig is the most neutral choice for “calm” or “not busy.”