Έφτιαξε έναν φανταστικό κόσμο.

Έφτιαξε is the 3rd person singular aorist of φτιάχνω.

That means it refers to a completed action in the past: he/she made, created, built, or put together.

So in this sentence, Έφτιαξε means something like he/she created or he/she made.

Greek often leaves out subject pronouns when they are not needed.

The verb ending in Έφτιαξε already tells you that the subject is 3rd person singular, so Greek does not need to say αυτός (he) or αυτή (she) unless there is special emphasis or contrast.

So:

• Έφτιαξε έναν φανταστικό κόσμο. = He/She created a fantastic world.
• Αυτός έφτιαξε έναν φανταστικό κόσμο. = He created a fantastic world.
  (with extra emphasis on he)

The dictionary form is φτιάχνω.

This verb can mean:

• make
• create
• build
• fix
• prepare

The exact English translation depends on context. In this sentence, create/make is the most natural choice.

Because κόσμο is a masculine singular noun, and it is the direct object of the verb.

The indefinite article changes form depending on gender and case:

• masculine accusative singular: έναν
• feminine accusative singular: μια / μία
• neuter accusative singular: ένα

Since κόσμος is masculine, Greek uses έναν.

A small extra note: in modern usage, the final -ν in words like έναν is sometimes omitted before certain consonants, so you may also see ένα φανταστικό κόσμο. But έναν φανταστικό κόσμο is completely normal and correct.

Because κόσμο is the accusative singular form, and the noun is the direct object of the verb.

The basic form is:

• ο κόσμος = the world / the world, society, people depending on context

In this sentence, the world is the thing being created, so Greek puts it in the accusative:

• nominative: ο κόσμος
• accusative: τον κόσμο / έναν κόσμο

So:

• Ο κόσμος είναι μεγάλος. = The world is big.
  (κόσμος = subject)
• Έφτιαξε έναν κόσμο. = He/She created a world.
  (κόσμο = object)

Because adjectives in Greek must agree with the noun they describe in:

• gender
• number
• case

Here, κόσμο is:

• masculine
• singular
• accusative

So the adjective must also be masculine singular accusative:

• nominative: φανταστικός
• accusative: φανταστικό

That is why the sentence has:

• έναν φανταστικό κόσμο

and not:

• έναν φανταστικός κόσμος

It can suggest more than one idea, depending on context.

φανταστικός can mean:

• fantastic
• wonderful
• amazing
• sometimes fantastical / imaginative

So έναν φανταστικό κόσμο could mean:

• a fantastic world
• an imaginative/fantastical world

If the sentence is about a writer, artist, or filmmaker, it often has the sense of a rich imaginary world.

Yes, it is normal.

Greek word order is more flexible than English word order because endings show grammatical relationships clearly.

So Έφτιαξε έναν φανταστικό κόσμο is a natural sentence. It can sound slightly narrative or neutral, like telling what happened.

Other orders are also possible, with different emphasis:

• Έφτιαξε έναν φανταστικό κόσμο.
  Neutral statement.

• Έναν φανταστικό κόσμο έφτιαξε.
  More emphasis on a fantastic world.

• Ο συγγραφέας έφτιαξε έναν φανταστικό κόσμο.
  Adds the subject explicitly: The writer created a fantastic world.

A rough English-friendly pronunciation is:

EH-ftia-kse

Notes:

• φ sounds like f
• φτ is pronounced ft
• ξ sounds like ks
• the stress is on the first syllable: Έφτιαξε

A rough pronunciation of the whole sentence is:

EH-ftia-kse e-NAN fan-da-sti-KO KOZ-mo

This is only an approximation, but it is close enough for a learner to get started.

Here it means world.

But κόσμος is a very common Greek word with several meanings, depending on context. It can mean:

• world
• people
• crowd
• society

In this sentence, because of έναν φανταστικό κόσμο, the meaning is clearly world, especially in the sense of a created or imagined world.