Απόψε θα μιλάω με τη φίλη μου όλο το βράδυ.

This is mainly a question of aspect.

• θα μιλάω uses the imperfective aspect, which presents the action as ongoing, repeated, or lasting over a period of time.
• θα μιλήσω uses the perfective aspect, which presents the action more as a single complete event.

Because the sentence also says όλο το βράδυ (all night), Greek naturally prefers θα μιλάω: it matches the idea of continuing for hours.

So:

• Απόψε θα μιλάω με τη φίλη μου όλο το βράδυ.
  = Tonight I’ll be talking with my friend all night.

Compare:

• Απόψε θα μιλήσω με τη φίλη μου.
  = Tonight I’ll speak / talk with my friend.

That second one is fine too, but it does not emphasize the long, ongoing duration in the same way.

θα is the particle used to form the future in Modern Greek.

So:

• μιλάω = I talk / I am talking
• θα μιλάω = I will be talking / I will talk

Greek does not form the future by changing the verb ending the way some languages do. Instead, it usually uses:

• θα + verb

So in this sentence:

• θα μιλάω = I will be talking

Yes. Both mean I speak / I am speaking / I talk.

They are just two common forms of the same verb:

• μιλάω
• μιλώ

Both are correct in Modern Greek. In everyday speech, μιλάω is often very common and feels very natural.

So you may see:

• θα μιλάω
• θα μιλώ

Both are acceptable, though θα μιλάω is especially common in everyday language.

Because με means with, and after it Greek uses the noun phrase in the form seen here:

• με = with
• τη φίλη μου = my friend

So:

• με τη φίλη μου = with my friend

A few useful parts:

• η φίλη = the female friend
• τη φίλη = the form used here after με
• μου = my

This is a very common structure in Greek:

• με τον φίλο μου = with my male friend
• με τη φίλη μου = with my female friend

Both are related to the same article.

The full form is την, but in everyday Modern Greek the final -ν is often dropped before many consonants.

So before φ in φίλη, you commonly get:

• τη φίλη

instead of

• την φίλη

Both may be seen, but τη φίλη is very normal and natural.

A simple way to think of it:

• την is the fuller form
• τη is the commonly shortened form before many consonants

In Greek, weak possessive forms like μου (my) usually come after the noun.

So Greek says:

• η φίλη μου
  literally: the friend my

But in natural English, that becomes:

• my friend

This post-noun position is very normal in Greek:

• το σπίτι μου = my house
• ο αδερφός μου = my brother
• η φίλη μου = my friend

So although it feels reversed from English, it is the standard Greek pattern.

Usually, η φίλη μου means my female friend.

If someone wants to clearly say my girlfriend, Greek very often uses:

• η κοπέλα μου

That said, context always matters, and sometimes φίλη μου could be interpreted differently depending on the situation. But for a learner, the safest understanding is:

• η φίλη μου = my female friend
• η κοπέλα μου = my girlfriend

Απόψε means tonight.

It refers specifically to this evening/tonight, usually in relation to what will happen later the same day.

It is similar to:

• σήμερα το βράδυ = this evening / tonight

But απόψε is shorter and very natural.

So:

• Απόψε θα μιλάω... = Tonight I’ll be talking...

This phrase means all night.

Word by word:

• όλο = whole / all
• το βράδυ = the night / the evening depending on context

So literally it is something like:

• the whole night

Greek often uses this structure:

• όλη τη μέρα = all day
• όλη τη νύχτα = all night
• όλο το βράδυ = all evening / all night

In this sentence, it emphasizes duration: the talking will continue throughout the night/evening.

Because Greek often keeps the article in expressions where English does not.

So Greek says:

• όλο το βράδυ
  literally: the whole night

But English usually prefers:

• all night

This is very common and natural in Greek. You should not try to match English word-for-word here.

Yes, Greek word order is more flexible than English word order.

The sentence as given is completely natural:

• Απόψε θα μιλάω με τη φίλη μου όλο το βράδυ.

But you could also hear variations such as:

• Απόψε όλο το βράδυ θα μιλάω με τη φίλη μου.
• Με τη φίλη μου θα μιλάω όλο το βράδυ απόψε.

These versions may shift the emphasis, but the core meaning stays similar.

Still, the original version is a very normal, neutral way to say it.

Yes, it sounds natural.

It gives the idea that tonight you will be talking with your friend continuously or for a long time, specifically all night.

Because of θα μιλάω plus όλο το βράδυ, it feels like:

• an ongoing activity
• something lasting for hours
• not just a single brief conversation

So the sentence is grammatically correct and very natural for that meaning.

Yes. That is also correct.

The difference is just that:

• τη φίλη μου is the common shortened form
• την φίλη μου keeps the final -ν

In everyday Greek, με τη φίλη μου is especially common and sounds very natural. So the version in your sentence is exactly what you should expect to hear a lot.