Später verhaftet die Polizei den Einbrecher.

German often puts a time word like später (later) at the beginning of a sentence to set the scene.

So instead of starting with the subject, German can start with:

• a time expression: Später ...
• a place expression
• an object
• many other sentence elements

Putting Später first gives it emphasis: Later, ...

This is very common and natural in German.

This is because German follows the verb-second rule in main clauses.

That means the finite verb must come in the second position in the sentence.

In this sentence:

1. Später = first position
2. verhaftet = second position
3. die Polizei = comes after the verb

So German is not following English word order here. It is following the rule:

• Später verhaftet die Polizei den Einbrecher.

If the subject comes first, then the order is:

• Die Polizei verhaftet später den Einbrecher.

Both are grammatical, but the emphasis is slightly different.

It counts as the first position.

In German grammar, position is more important than simply counting words. A whole phrase can fill the first position.

Here, Später is just one word, so that is easy to see. But compare:

• Am nächsten Morgen verhaftet die Polizei den Einbrecher.

The whole phrase Am nächsten Morgen takes the first position, and the verb still has to come second.

So the rule is really:

• one element before the verb
• finite verb in second position

Yes, this is an important difference.

In English, the police is grammatically plural:

• The police arrest the burglar.

In German, die Polizei is usually treated as a singular feminine noun:

• Die Polizei verhaftet den Einbrecher.

That is why the verb is singular:

• die Polizei verhaftet not
• die Polizei verhaften

So even though it refers to the police as an institution or force, grammatically it behaves like a singular noun.

Because den Einbrecher is in the accusative case, which marks the direct object.

Here:

• die Polizei = the subject, the one doing the arresting
• den Einbrecher = the direct object, the person being arrested

The noun Einbrecher itself does not change here, but the article does:

• der Einbrecher = nominative
• den Einbrecher = accusative

So the article tells you the role of the noun in the sentence.

You know mainly because of the case marking.

• die Polizei is nominative here, so it is the subject
• den Einbrecher is accusative, so it is the direct object

German often lets you identify sentence roles through articles and case endings, not just word order.

That is very useful, because German word order is more flexible than English.

Yes, verhaftet is formally present tense.

German, like English, can use the present tense in several ways depending on context:

• for something happening now
• for something habitual
• for planned or future events
• in storytelling, to make events feel vivid

So Später verhaftet die Polizei den Einbrecher can mean something like:

• Later, the police arrest the burglar or in natural English,
• Later, the police arrest the burglar / later the police will arrest the burglar

The exact time sense depends on the context.

Yes, that is grammatical.

Compare:

• Später verhaftet die Polizei den Einbrecher.
• Die Polizei verhaftet später den Einbrecher.

Both mean basically the same thing, but the focus changes.

• Später ... puts emphasis on when
• Die Polizei ... starts more neutrally with the subject

German word order is often used to manage focus and information structure, not just grammar.

Because Später is just a normal adverb in the sentence, not a separate introductory phrase that requires a comma.

German usually does not put a comma after a simple sentence adverb at the beginning:

• Heute gehe ich nach Berlin.
• Morgen kommt er.
• Später verhaftet die Polizei den Einbrecher.

A comma would normally be wrong here.

Yes. That would be a more explicit future construction.

Compare:

• Später verhaftet die Polizei den Einbrecher.
  Present tense used with future meaning or in narration.

• Später wird die Polizei den Einbrecher verhaften.
  More clearly future.

In everyday German, the simple present is often enough when the time is already clear from words like später, morgen, nächste Woche, and so on.

So the original sentence is perfectly normal grammatically.

Yes, grammatically it is fine and natural.

That said, whether it sounds fully natural depends on context. It works especially well:

• in a story
• in a sequence of events
• when contrasting now and later

For example:

• Zuerst flieht der Täter. Später verhaftet die Polizei den Einbrecher.

Without context, it can sound a little like a written narrative or a summary of events, but it is still good German.

The three biggest points are:

1. Verb-second word order

   • Später verhaftet ...
   • not Später die Polizei verhaftet ...

2. Case

   • die Polizei = subject
   • den Einbrecher = object

3. Polizei is singular in German

   • die Polizei verhaftet
   • not die Polizei verhaften

If you understand those three things, you understand most of the grammar of this sentence.