Μίλησε εξαιρετικά καλά.

Μίλησε is the aorist form of μιλάω / μιλώ (to speak, to talk).

In this sentence, it most naturally means:

• he spoke
• she spoke
• it spoke (rare, depending on context)

So μίλησε εξαιρετικά καλά means something like He/She spoke extremely well.

The aorist is the usual Greek past tense for a completed event. It does not mean was speaking; for that, Greek would use a different form, such as μιλούσε.

Greek often does not need subject pronouns because the verb ending already shows the person and number.

So:

• μίλησε = he/she/it spoke

You can add a pronoun like αυτός or αυτή, but usually you only do that for emphasis, contrast, or clarity.

For example:

• Αυτή μίλησε εξαιρετικά καλά. = She spoke extremely well.
  This sounds more emphatic, like She spoke extremely well.

Both are adverbs.

• καλά = well
• εξαιρετικά = exceptionally / extremely

Here, εξαιρετικά modifies καλά, not just the verb by itself. So the structure is:

• μίλησε = spoke
• καλά = well
• εξαιρετικά καλά = extremely well / exceptionally well

So the phrase works like English very well or extremely well.

In Modern Greek, καλά is the normal everyday adverb meaning well in sentences like this:

• Μιλάει καλά ελληνικά. = He/She speaks Greek well.

Καλώς does exist, but it is more formal, old-fashioned, or used in fixed expressions, such as:

• Καλώς ήρθες. = Welcome.

So in normal spoken Modern Greek, μίλησε καλά is the natural choice.

Yes. Μίλησε can also be the singular imperative of the verb, meaning:

• Speak!
• Talk!

So by itself, μίλησε is technically ambiguous.

However, in this sentence, Μίλησε εξαιρετικά καλά, the most natural reading is the past tense:

• He/She spoke extremely well.

A command like Speak extremely well! is grammatically possible, but much less likely in ordinary context.

The accent shows the correct pronunciation and stress:

• Μί-λη-σε
• stress on the first syllable

Greek spelling uses written accents, and they matter both for pronunciation and for writing correctly.

The whole sentence is pronounced roughly like:

• MEE-li-se ek-se-re-ti-KA ka-LA

The stressed syllables are:

• Μίλησε
• εξαιρετικά
• καλά

Not exactly.

• μίλησε = spoke / talked
• είπε = said

So:

• Μίλησε εξαιρετικά καλά. = He/She spoke extremely well.
• Το είπε πολύ καλά. = He/She said it very well.

Use μιλάω / μιλώ when focusing on speaking in general, and λέω / είπε when focusing on what was said.

Yes, Greek word order is fairly flexible, but some orders sound more natural than others.

The most neutral order here is:

• Μίλησε εξαιρετικά καλά.

You may also see:

• Μίλησε καλά εξαιρετικά. — this sounds unnatural
• Εξαιρετικά καλά μίλησε. — possible, with emphasis on how well
• Καλά μίλησε. — possible in some contexts, often with contrast or emphasis

So for a learner, Μίλησε εξαιρετικά καλά is the best standard pattern.

Greek often builds this idea by combining:

• an adverb of degree: εξαιρετικά
• with the basic adverb: καλά

That is very similar to English:

• very well
• really well
• extremely well

So Greek is not using two separate ideas here; it is making one stronger adverb phrase:

• εξαιρετικά καλά = extremely well

Yes, absolutely.

• Μίλησε πολύ καλά. = He/She spoke very well.
• Μίλησε εξαιρετικά καλά. = He/She spoke extremely / exceptionally well.

The difference is mainly one of strength and style:

• πολύ καλά = more common, everyday
• εξαιρετικά καλά = stronger, more polished, sometimes a bit more formal or expressive

This is a very important Greek tense/aspect contrast.

• μίλησε = he/she spoke
  A single completed event
• μιλούσε = he/she was speaking / used to speak
  Ongoing, repeated, or background action

Compare:

• Μίλησε εξαιρετικά καλά. = He/She spoke extremely well.
• Μιλούσε εξαιρετικά καλά. = He/She was speaking extremely well or used to speak extremely well, depending on context

So μίλησε gives you a completed whole event.

It is neutral and completely natural in both speech and writing.

None of the words are slang.
The adverb εξαιρετικά sounds a little more polished than πολύ, but the sentence itself is still very normal Modern Greek.

So you could use it in:

• everyday conversation
• class comments
• presentations
• writing about someone's performance

Yes. It is a fully complete sentence.

Greek does not need:

• an explicit subject like he/she
• an object
• any extra article or pronoun here

So Μίλησε εξαιρετικά καλά. is a perfectly normal complete sentence meaning:

• He/She spoke extremely well.

The context will tell you who spoke.