Die Schlafzeit der Kinder beginnt um acht Uhr.

The children's bedtime begins at eight o'clock.

Breakdown of Die Schlafzeit der Kinder beginnt um acht Uhr.

• das Kind: the child
• die Uhr: the clock
• acht: eight
• beginnen: to begin
• um: at
• der: the; (plural, genitive)
• die Schlafzeit: the sleeping time

Questions & Answers about Die Schlafzeit der Kinder beginnt um acht Uhr.

Why is the article Die used with Schlafzeit? Why not Der or Das?

In German, every noun has a grammatical gender: masculine (der), feminine (die), or neuter (das).

• Schlafzeit is grammatically feminine.
• The definite article for feminine nouns in the nominative singular is die.

So:

• die Schlafzeit = the bedtime / sleeping time
• If it were masculine, it would be der Schlafzeit (it isn’t)
• If it were neuter, it would be das Schlafzeit (it isn’t)

You simply have to learn with the noun: die Schlafzeit.

Why is it Schlafzeit written as one word and capitalized?

Two reasons:

1. Compound nouns are written together in German.

   • Schlaf (sleep) + Zeit (time) → Schlafzeit (sleep time / bedtime)
     You don’t write Schlaf Zeit as two words.

2. All nouns are capitalized in German.

   • Schlafzeit is a noun, so it must start with a capital letter.
   • Kinder (children) is also a noun, so it is capitalized too.

What is the function of der Kinder in this sentence, and why that form?

Der Kinder is a genitive plural and expresses possession: the children’s.

• Nominative plural: die Kinder (the children)
• Genitive plural: der Kinder (of the children)

So die Schlafzeit der Kinder literally means the sleep-time of the children = the children’s bedtime.

In German, the genitive is often used for possession:

• das Buch des Lehrers = the teacher’s book
• die Schlafzeit der Kinder = the children’s bedtime

Could I say die Schlafzeit von den Kindern instead of der Kinder?

You can say die Schlafzeit von den Kindern, and it is grammatically acceptable, but:

• die Schlafzeit der Kinder (genitive) sounds more natural and stylistically better, especially in written or neutral German.
• von + dative (like von den Kindern) is more colloquial and often used in speech.

So:

• More standard: die Schlafzeit der Kinder
• More casual: die Schlafzeit von den Kindern

Why is it Kinder and not Kindern?

Because Kinder here is in the genitive plural, and in the genitive plural the article changes, but the noun Kinder itself does not:

• Nominative plural: die Kinder
• Dative plural: den Kindern
• Genitive plural: der Kinder

So after der (genitive plural) the correct form is Kinder, not Kindern.

Why does the verb beginnt come after die Schlafzeit der Kinder?

German main clauses follow the verb-second (V2) rule:

• The finite verb (the conjugated verb) must be in second position in the sentence.

In Die Schlafzeit der Kinder beginnt um acht Uhr.:

1. Die Schlafzeit der Kinder = first position (this whole phrase counts as one element)
2. beginnt = second position (the verb)
3. um acht Uhr = the rest of the sentence

So the word order here is standard German main-clause word order.

Can I put um acht Uhr at the beginning of the sentence?

Yes. That is very natural and even quite common:

• Um acht Uhr beginnt die Schlafzeit der Kinder.

The rule still holds:

1. Um acht Uhr = first position
2. beginnt = second position
3. die Schlafzeit der Kinder = the rest

German allows you to move time, place, etc. to the beginning for emphasis, as long as the conjugated verb stays in second position.

Why is the preposition um used with the time, and what does it mean exactly?

With clock times, German normally uses um to mean at:

• um acht Uhr = at eight o’clock
• um drei Uhr = at three o’clock
• Die Schule beginnt um neun Uhr. = School begins at nine o’clock.

So in this sentence:
beginnt um acht Uhr = begins at eight o’clock.

Other prepositions like bei, an, or in are not used for stating exact clock times.

Why is it acht Uhr and not something like um acht only or um zwanzig Uhr?

All three are possible, but they differ slightly:

• um acht Uhr – neutral, standard
• um acht – more colloquial; you can drop Uhr in everyday speech
• um zwanzig Uhr – uses the 24‑hour clock (20:00), common in timetables, formal info, etc.

So you might hear:

• Die Schlafzeit der Kinder beginnt um acht Uhr.
• Die Schlafzeit der Kinder beginnt um acht. (informal)
• Die Schlafzeit der Kinder beginnt um zwanzig Uhr. (sounds like a schedule, very formal/official)

What exactly is the verb beginnt, and is there an alternative?

Beginnt is:

• the 3rd person singular present of beginnen (to begin):
  • ich beginne
  • du beginnst
  • er/sie/es beginnt

So:

• Die Schlafzeit der Kinder beginnt um acht Uhr.
  = The children’s bedtime begins at eight o’clock.

A very common alternative verb is anfangen:

• Die Schlafzeit der Kinder fängt um acht Uhr an.

Both are correct; beginnen is often a bit more neutral/formal, anfangen slightly more conversational.

Is Schlafzeit the most natural word for “bedtime”, or is Schlafenszeit better?

Both exist, but they have different feels:

• Schlafzeit – a bit more formal or technical: the period of time designated for sleep.
• Schlafenszeit – very idiomatic for bedtime, especially with children.

Native speakers would often say:

• Die Schlafenszeit der Kinder beginnt um acht Uhr.

or more commonly even:

• Die Kinder gehen um acht Uhr ins Bett. (The children go to bed at eight o’clock.)
• Um acht Uhr ist Schlafenszeit für die Kinder.

Your original sentence with Schlafzeit is correct and understandable, just slightly more neutral/abstract.

Is this sentence talking about a regular habit or just today?

Grammatically, it is simple present tense, which in German (like in English) can express:

• a regular habit:
  Die Schlafzeit der Kinder beginnt um acht Uhr.
  = The children’s bedtime (always/generally) begins at eight o’clock.

• or a scheduled event (like today or in a plan):
  Heute beginnt die Schlafzeit der Kinder um acht Uhr.

Context (adverbs like immer, heute, normalerweise) will clarify whether it’s habitual or just for a particular day.