Ο κωδικός PIN είναι σωστός.

Ο is the masculine singular definite article, meaning the.

It appears here because κωδικός is a masculine singular noun, so the article has to match it:

• ο κωδικός = the code

Greek articles change for gender, number, and case, unlike English the, which always stays the same.

Κωδικός means code, and PIN is the borrowed acronym PIN.

So ο κωδικός PIN literally means the PIN code.

This is very common in Greek: a Greek noun is used together with an English acronym or foreign term.

You may also hear simply:

• το PIN

But ο κωδικός PIN is perfectly natural and a bit more explicit.

In Greek, every noun has a grammatical gender: masculine, feminine, or neuter.

Κωδικός is a masculine noun, so it takes masculine forms around it:

• ο κωδικός
• σωστός (masculine form of correct/right)

This is grammatical gender, not biological gender.

Because it has to agree with κωδικός, which is masculine singular.

Greek adjectives change form to match the noun they describe:

• masculine: σωστός
• feminine: σωστή
• neuter: σωστό

So in this sentence:

• ο κωδικός → masculine singular
• therefore σωστός must also be masculine singular

Yes, absolutely. That is very common.

• Το PIN είναι σωστό. = The PIN is correct.

Here, PIN is treated as neuter, which is common for foreign words and acronyms in Greek.

So both of these are natural, though they are structured slightly differently:

• Ο κωδικός PIN είναι σωστός.
• Το PIN είναι σωστό.

In the first sentence, the head noun is κωδικός, which is masculine. In the second, the head word is PIN, often treated as neuter.

In this kind of sentence, Greek normally uses είναι = is.

So:

• Ο κωδικός PIN είναι σωστός.

is the normal full sentence.

Greek can sometimes omit words in informal situations, headings, labels, or very short answers, but in a standard statement like this, είναι is expected.

Not completely. Greek word order is more flexible than English.

The neutral, standard order is:

• Ο κωδικός PIN είναι σωστός.

But other orders are possible for emphasis, for example:

• Σωστός είναι ο κωδικός PIN.
• Ο κωδικός PIN σωστός είναι. (less neutral, more marked)

English relies heavily on word order for grammar, but Greek uses endings much more, so word order can shift more easily.

Here σωστός means something like correct or right.

Depending on context, it can also mean:

• correct
• right
• proper

With a PIN, password, answer, or number, σωστός usually means correct.

Examples:

• σωστό PIN = correct PIN
• σωστή απάντηση = correct answer

A rough pronunciation guide:

• Ο = o
• κωδικός = ko-thee-KOS
  (modern Greek δ sounds like th in this)
• PIN = usually pronounced like the English acronym or adapted in Greek speech
• είναι = EE-ne
• σωστός = so-STOS

A fuller rough version:

• o ko-thee-KOS pin EE-ne so-STOS

The stress marks matter:

• κωδικός
• είναι
• σωστός

Because PIN is an international acronym, and Greek often keeps such acronyms in their original script, especially in technology, banking, and official contexts.

In everyday Greek, foreign acronyms are very often left as they are:

• PIN
• SMS
• Wi-Fi

The surrounding Greek words show the grammar, so the sentence still works naturally even if one word is not written in Greek letters.

It is in the nominative singular.

You can tell because it is the subject of the sentence:

• Ο κωδικός PIN = the subject
• είναι σωστός = is correct

So the pattern is:

• subject in nominative
  • είναι
    • adjective

The adjective σωστός also appears in the nominative masculine singular to match the subject.

In a normal statement like this, the article is natural and expected:

• Ο κωδικός PIN είναι σωστός.

If you remove it:

• Κωδικός PIN είναι σωστός.

that sounds less natural in ordinary Greek unless it appears in a special context such as notes, headings, or telegraphic style.

Greek uses the definite article more often than English does, so learners should get used to seeing it frequently.