Ο θαυμαστής λέει ότι το άλμπουμ είναι αξέχαστο.

Ο is the masculine singular nominative definite article, equivalent to the.

In Ο θαυμαστής, it tells you that θαυμαστής is:

• masculine
• singular
• the subject of the sentence

Greek articles change form depending on gender, number, and case, unlike English the, which never changes.

Θαυμαστής is a masculine noun. In this sentence it is in the nominative singular, because it is the subject.

The ending -ής is a common masculine noun ending in Greek. Many nouns of this type change in other cases, so you may later see forms like:

• nominative: ο θαυμαστής
• genitive: του θαυμαστή

So here, ο θαυμαστής is simply the basic dictionary-style subject form.

Λέει is the 3rd person singular present tense of λέω = to say / to tell.

So:

• λέω = I say
• λες = you say
• λέει = he/she/it says

In this sentence, the subject is ο θαυμαστής, so λέει matches he says.

A useful thing to notice: in modern Greek, λέει is a very common everyday form.

Ότι introduces a content clause, meaning it works like English that in a sentence such as He says that...

So the structure is:

• Ο θαυμαστής λέει = The fan says
• ότι το άλμπουμ είναι αξέχαστο = that the album is unforgettable

In Greek, ότι is very common after verbs of saying, thinking, knowing, etc.

You may also encounter πως in similar situations in modern Greek, especially in everyday language:

• Λέει ότι...
• Λέει πως...

Both can often mean the same thing here.

No. This is a very common learner question.

• ότι = that
• ό,τι = whatever / anything that

The comma-like mark inside ό,τι matters.

In your sentence, ότι is the conjunction meaning that:

• λέει ότι... = says that...

It is not ό,τι.

Yes. Άλμπουμ is treated as a neuter noun, so it takes the neuter article το.

That is why you get:

• το άλμπουμ

This noun is a loanword, and in modern Greek it is commonly used as an indeclinable noun, meaning its form often stays the same across cases, while the article shows the grammar.

So even if the noun itself does not visibly change much, the article helps you see its role.

Είναι is the present tense form of είμαι = to be used for he/she/it is and also they are.

Here the subject of the second clause is το άλμπουμ, which is singular, so:

• το άλμπουμ είναι = the album is

This is one of those Greek verb forms that learners quickly get used to because it appears extremely often.

Because it agrees with το άλμπουμ, which is neuter singular.

Greek adjectives must agree with the noun they describe in:

• gender
• number
• case

So the adjective αξέχαστος / αξέχαστη / αξέχαστο changes form depending on the noun:

• masculine: αξέχαστος
• feminine: αξέχαστη
• neuter: αξέχαστο

Since άλμπουμ is neuter singular, the correct form is αξέχαστο.

The word order here is very natural and straightforward:

• Ο θαυμαστής = subject
• λέει = verb
• ότι... = subordinate clause
• το άλμπουμ = subject inside the subordinate clause
• είναι αξέχαστο = is unforgettable

Greek word order is generally more flexible than English, because endings and articles carry a lot of grammatical information. But this sentence uses a very standard order that is easy for learners to recognize.

In normal Greek, the article is usually used with a noun like this, so ο θαυμαστής sounds natural.

Leaving it out would usually sound less natural unless you are speaking in a special style, such as:

• dictionary-like language
• headlines
• very telegraphic speech

So for ordinary sentences, keep the article:

• Ο θαυμαστής λέει...

Likewise:

• το άλμπουμ

Greek uses the definite article much more regularly than English in many situations.

The accent marks show which syllable is stressed in pronunciation.

For example:

• θαυμαστής
• λέει
• ότι
• άλμπουμ
• είναι
• αξέχαστο

These marks are important in written Greek and should not be ignored.

A rough stress guide:

• θαυμαστής
• λέει
• ότι
• άλμπουμ
• είναι
• αξέχαστο

Even if your pronunciation is not perfect yet, paying attention to stress will make your Greek sound much more natural.

This is useful because it shows agreement clearly.

If the subject of the first clause changed, the verb λέει would also change if needed:

• Η θαυμάστρια λέει ότι το άλμπουμ είναι αξέχαστο.
  A female fan says that the album is unforgettable.

• Οι θαυμαστές λένε ότι το άλμπουμ είναι αξέχαστο.
  The fans say that the album is unforgettable.

Notice:

• ο θαυμαστής → masculine singular
• η θαυμάστρια → feminine singular
• οι θαυμαστές → plural
• λέει → singular
• λένε → plural

But the second clause stays the same because το άλμπουμ is still singular neuter:

• το άλμπουμ είναι αξέχαστο

Sometimes in informal speech Greek may restructure things, but in a sentence like this, keeping ότι is the clearest and most standard choice.

English often says:

• The fan says the album is unforgettable

Greek more naturally keeps the connector:

• Ο θαυμαστής λέει ότι το άλμπουμ είναι αξέχαστο.

So as a learner, it is safest to use ότι after λέει when introducing the clause.