Ο καθηγητής με τη μακριά γενειάδα μιλάει πάντα ήρεμα.

Because καθηγητής is a masculine singular noun here, and it is the subject of the sentence, so it appears in the nominative case.

• ο = the masculine singular nominative article
• καθηγητής = professor / teacher

So ο καθηγητής means the professor.

Greek uses the definite article very often, sometimes more often than English does. In this sentence, ο καθηγητής refers to a specific professor, so the article is natural and expected.

Greek learners often notice that articles appear in many places where English might be a bit looser. Here, though, English also uses one: the professor.

This is a prepositional phrase describing the professor.

• με = with
• τη μακριά γενειάδα = the long beard

So the whole phrase means with the long beard.

It tells you which professor we are talking about: the one with the long beard.

After με, Greek normally uses the accusative case.

So:

• τη = feminine singular accusative article
• μακριά = feminine singular accusative adjective
• γενειάδα = feminine singular accusative noun

They all match because they belong together as one noun phrase.

Both are related forms of the feminine accusative singular article.

In modern Greek, the final -ν in την is often dropped before certain consonants, especially in everyday usage. So τη γενειάδα is perfectly normal.

You may also see την in writing or before vowels and certain consonants. So:

• τη γενειάδα = common and correct
• την γενειάδα = also possible in some contexts/styles

Because it has to agree with γενειάδα.

γενειάδα is:

• feminine
• singular
• accusative

So the adjective must also be:

• feminine
• singular
• accusative

That gives us μακριά.

This is a very important Greek pattern: adjectives agree with the noun they describe.

Yes. μιλάει and μιλά are both acceptable forms of the 3rd person singular present of μιλάω / μιλώ.

So both of these can mean he/she speaks:

• μιλάει
• μιλά

In everyday modern Greek, μιλάει is very common and sounds natural.

Because here the word describes how he speaks, not what he is like.

• ήρεμος = calm, calm person, calm man
• ήρεμα = calmly

So:

• Ο καθηγητής είναι ήρεμος. = The professor is calm.
• Ο καθηγητής μιλάει ήρεμα. = The professor speaks calmly.

In Greek, many adverbs are identical to the neuter singular form of the adjective, which is why ήρεμα looks adjective-like.

πάντα means always.

It tells you how often the action happens:

• μιλάει = speaks
• πάντα = always
• ήρεμα = calmly

So the sentence says that the professor always speaks calmly.

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

This sentence is very natural:

• Ο καθηγητής με τη μακριά γενειάδα μιλάει πάντα ήρεμα.

But you could also hear variations such as:

• Ο καθηγητής με τη μακριά γενειάδα πάντα μιλάει ήρεμα.
• Πάντα μιλάει ήρεμα ο καθηγητής με τη μακριά γενειάδα.

The meaning stays basically the same, but the emphasis can shift slightly. The original version is a very neutral, natural way to say it.

Yes. Greek often uses a phrase with με to describe a person by something they have.

So ο καθηγητής με τη μακριά γενειάδα is literally:

the professor with the long beard

English might also express the same idea as:

the long-bearded professor

Greek usually keeps the with structure here, and that sounds completely normal.

A rough pronunciation guide is:

o kathiyitís me ti makriá yeniáda milái pánda írema

A few useful pronunciation notes:

• γ before ε or ι is a soft sound, somewhat like a voiced y-like sound in the mouth
• η, ι, υ, ει, οι are all pronounced like ee in modern Greek
• the written accents show which syllable is stressed:
  • καθηγητής
  • μακριά
  • γενειάδα
  • μιλάει
  • πάντα
  • ήρεμα

Because in Greek, when you have article + adjective + noun, the article normally appears with the noun phrase.

So this pattern is standard:

• τη μακριά γενειάδα = the long beard

Greek does not usually drop the article the way English can in phrases like with long hair or with long beard. Greek strongly prefers the full phrase with article here.

Yes, depending on context.

In many contexts, καθηγητής can mean:

• teacher, especially at secondary school level
• professor, especially in higher education

So the exact English translation depends on the situation. In this sentence, if the meaning shown to the learner is professor, that is perfectly fine.