Die Kontoverbindung ist korrekt.

Kontoverbindung usually means bank account details rather than just bank account.

In real-life German, it often refers to the information needed for a payment, such as:

• the account holder
• the IBAN
• sometimes the BIC
• the bank information in general

So Die Kontoverbindung ist korrekt means that the banking details on file are correct.

Because Kontoverbindung is a feminine noun, so its nominative singular article is die.

A useful rule for compound nouns in German is:

The last part of the compound decides the gender.

Here, the last part is Verbindung, and die Verbindung is feminine.
So:

• die Verbindung
• die Kontoverbindung

Yes. German commonly combines nouns into one compound word.

Here:

• Konto = account
• Verbindung = connection / link / details in this context

Together, Kontoverbindung becomes a single noun.

This is very normal in German. English often uses several words where German uses one compound noun.

It is in the nominative case because it is the subject of the sentence.

The structure is:

• Die Kontoverbindung = subject
• ist = verb
• korrekt = predicate adjective

So the sentence follows the basic pattern:

Subject + verb + adjective

Because German main clauses normally follow the verb-second rule.

In a normal statement, the finite verb comes in position 2:

• Die Kontoverbindung ist korrekt.

Here:

1. Die Kontoverbindung
2. ist

This is one of the most important basic word-order rules in German.

Because korrekt is used predicatively, after the verb sein.

In German:

• attributive adjective before a noun gets an ending
  
  • die korrekte Kontoverbindung
• predicative adjective after sein, werden, bleiben, etc. does not get an ending
  
  • Die Kontoverbindung ist korrekt.

So korrekt stays in its basic form here.

Yes, that is possible, and the meaning is very similar.

But there is a slight nuance:

• korrekt sounds a bit more formal, precise, or official
• richtig is very common and slightly more general

In a banking or administrative context, korrekt sounds especially natural.

Not usually. If you want to say bank account, the normal word is Konto.

Compare:

• das Konto = the account
• die Kontoverbindung = the account details / banking information

So if you say Die Kontoverbindung ist korrekt, you are usually talking about the payment details, not simply the existence of the account itself.

Normally, no. In standard German, you would usually need the article:

• Die Kontoverbindung ist korrekt.

Leaving out the article sounds incomplete in an ordinary sentence.
You might see article omission in:

• headings
• forms
• notes
• very telegraphic style

But as a full normal sentence, the version with die is the natural one.

You move the verb to the first position:

Ist die Kontoverbindung korrekt?

That is the standard way to form a yes/no question in German.

Statement:

• Die Kontoverbindung ist korrekt.

Question:

• Ist die Kontoverbindung korrekt?

It is neutral and quite natural, but it sounds especially common in formal or administrative contexts, such as:

• banking
• invoices
• customer service
• online forms
• official emails

In casual everyday conversation, people might more often say something like:

• Die Bankdaten stimmen.
• Die Kontodaten sind richtig.

But Die Kontoverbindung ist korrekt is perfectly normal and correct.

They are similar, but not always identical.

• Kontoverbindung: bank account details; a common formal term
• Kontodaten: account data/details; also common
• Bankdaten: bank details; slightly broader and very common in everyday use

In many practical situations, people use them almost interchangeably.
But Kontoverbindung often sounds a bit more official or business-like.

Then you would put the adjective before the noun, and it would need an ending:

die korrekte Kontoverbindung

That is different from:

• Die Kontoverbindung ist korrekt. = The bank details are correct.
• die korrekte Kontoverbindung = the correct bank details

This is a very useful contrast for learning adjective endings in German.