Learn Hardcore German: Die Temperatur sinkt in der Nacht.

sinkt is the 3rd-person singular present form of the verb sinken, which means “to sink,” “to drop,” or “to decrease.” So Die Temperatur sinkt translates as “The temperature drops” or “The temperature is dropping.”

Why is the finite verb (sinkt) in the second position?

German main clauses follow the V2 rule: the finite verb must occupy the second slot. Whether you start with the subject, a time expression, or another element, the conjugated verb stays in position two.

What role does die Temperatur play, and why is there no object after sinkt?

die Temperatur is the subject of the sentence, so it’s in the nominative case. The verb sinken is intransitive, meaning it doesn’t take a direct object— it simply describes the subject’s change of state.

Why is Nacht in the dative case after in, and why do we use in here?

When in expresses time (when something happens) rather than movement, it governs the dative case. Thus in + der (dative feminine) → in der Nacht, meaning “during the night” or “at night.”

Why is the article der used with Nacht instead of dem?

In the dative singular, der is the article for feminine nouns. dem is the dative singular article for masculine and neuter nouns, so it doesn’t apply to Nacht, which is feminine.

Why can’t we say am Nacht like we say am Abend?

am is a contraction of an + dem and only works for masculine and neuter nouns. Abend is masculine (der Abend → am Abend), but Nacht is feminine, so you must say in der Nacht or während der Nacht.

Could we use nachts instead of in der Nacht? Are they interchangeable?

Yes. nachts is an adverb meaning “at night” and conveys the general time. in der Nacht is a prepositional phrase emphasizing “during the night” often with more specificity, but both are idiomatic. E.g. Die Temperatur sinkt nachts is perfectly normal.

Can we say Die Temperatur fällt in der Nacht rather than sinkt? What’s the difference?

Yes. Both fallen (“to fall”) and sinken (“to sink,” “drop”) are commonly used to describe a decrease in temperature. sinken can sound slightly more formal or technical, but they’re largely interchangeable here.

Can I start the sentence with the time expression, e.g. In der Nacht sinkt die Temperatur? How does that affect word order?

Absolutely. Fronting in der Nacht to position one still keeps the verb sinkt in slot two, and the subject die Temperatur moves to slot three. The meaning remains the same, though the emphasis shifts to the time element.