Правонарушение произошло ночью.

at night

Breakdown of Правонарушение произошло ночью.

• произойти: to happen
• правонарушение: the administrative offence

Questions & Answers about Правонарушение произошло ночью.

Why is произошло in the neuter form?

Because the subject, правонарушение, is a neuter singular noun.

In the past tense, Russian verbs agree with the subject in gender and number:

• masculine: произошёл
• feminine: произошла
• neuter: произошло
• plural: произошли

So:

• правонарушение произошло
• авария произошла
• инцидент произошёл

What case is правонарушение here?

It is in the nominative case because it is the subject of the sentence — the thing that occurred.

So in Правонарушение произошло ночью, the structure is basically:

• Правонарушение = the offense/violation
• произошло = occurred
• ночью = at night

What case is ночью, and why?

Ночью is the instrumental singular of ночь.

Russian often uses certain nouns in the instrumental case as adverbial expressions of time, especially parts of the day:

• утром = in the morning
• днём = in the daytime / during the day
• вечером = in the evening
• ночью = at night

So ночью does not literally mean by night in normal modern usage. It simply means at night or during the night.