Learn Hardcore Greek: Κάθομαι στο αμφιθέατρο και περιμένω να αρχίσει η διάλεξη του καθηγητή. - I sit in the lecture hall and wait for the professor’s lecture to start.

“I am sitting” / “I am seated” (state)
It can also mean “I sit down” in some contexts, but for the action “to sit down” Greek often uses κάθομαι or κάτσω depending on aspect and context.

Greek doesn’t have a separate continuous form like English “I am sitting” vs “I sit”. The simple present κάθομαι can cover both:

Κάθομαι στο αμφιθέατρο.
→ “I am sitting in the lecture hall.” (right now)

Here, because you also have περιμένω (“I am waiting”), the context is clearly “right now”, so κάθομαι is understood as “I am sitting”, not a general habit.

Why is it στο αμφιθέατρο and not just σε αμφιθέατρο?

Στο is a contraction of the preposition σε + the definite article το:

σε + το = στο

So:

στο αμφιθέατρο = “in the amphitheater / lecture hall” (a specific one)
σε αμφιθέατρο = “in an amphitheater” (any amphitheater, very rare in this context)

In Greek, you normally use the definite article much more than in English, especially with places:

στο σχολείο – “at school”
στο σπίτι – “at home / to the house”
στο αμφιθέατρο – “in the amphitheater”

Here, the speaker is in some particular amphitheater (e.g. where the class is), so στο is expected.

What exactly does αμφιθέατρο mean in modern Greek? Is it just “amphitheater”?

Αμφιθέατρο literally is “amphitheater”, but in modern Greek, especially in everyday university context, it usually means:

a large lecture hall or
a tiered classroom with rows of seats going up.

So:

στο αμφιθέατρο in a university setting is very naturally understood as “in the lecture hall”, not necessarily an ancient-style open-air amphitheater.

The same word is also used for theater-like venues with tiered seating.

Why do we say περιμένω να αρχίσει and not just περιμένω αρχίζει?

In Greek, many verbs that express wanting, waiting, trying, planning, starting, etc. are followed by να + subjunctive, not by a bare present tense.

Περιμένω (I wait / I am waiting) is one of these verbs. The usual pattern is:

περιμένω να + [subjunctive]

So:

περιμένω να αρχίσει
literally: “I am waiting for it to start.”

Using αρχίζει directly after περιμένω (περιμένω αρχίζει) is ungrammatical in standard Greek. You need the να to introduce a subordinate clause with the subjunctive.

Why is it να αρχίσει and not να αρχίζει? What is the difference?

Both να αρχίσει and να αρχίζει are subjunctive forms of αρχίζω, but they differ in aspect:

να αρχίσει – aorist subjunctive (focus on the single event of starting)
να αρχίζει – present subjunctive (focus on the ongoing process or repeated action)

With περιμένω, you usually wait for one event to happen (the lecture to start once), so Greek uses the aorist subjunctive:

περιμένω να αρχίσει η διάλεξη.
“I’m waiting for the lecture to (begin / start).”

Περιμένω να αρχίζει η διάλεξη would sound strange in this context and would suggest something like “I am waiting for the (habitual) starting of the lecture”, which is not what you mean here.

Why is the article η used with διάλεξη? How do I know it’s feminine?

Διάλεξη is a feminine noun, so it takes the feminine article η in the nominative singular:

η διάλεξη – the lecture

Greek articles agree with the noun in:

gender (masculine / feminine / neuter)
number (singular / plural)
case (nominative / genitive / accusative, etc.)

For διάλεξη:

Nominative singular: η διάλεξη
Genitive singular: της διάλεξης
Accusative singular: τη(ν) διάλεξη

There’s no rule from the ending -η alone that always guarantees “feminine”, but many feminine nouns in modern Greek end in -η or -ξη (like η λέξη, η τάξη, η διάλεξη), so you learn them as you go.

Why is it η διάλεξη του καθηγητή and not η διάλεξη ο καθηγητής or something similar?

Here, του καθηγητή is in the genitive case, showing possession or relation:

η διάλεξη του καθηγητή
= “the lecture of the professor / the professor’s lecture”.

Patterns:

η διάλεξη – nominative (subject: “the lecture”)
του καθηγητή – genitive (possessor: “of the professor”)

If you said η διάλεξη ο καθηγητής, you’d be putting ο καθηγητής in the nominative, which would sound like you are starting a new subject (“the professor”), and the structure would be ungrammatical here.

The normal Greek order for “the professor’s lecture” is:

[article + noun] + [genitive phrase]
→ η διάλεξη του καθηγητή

Can του καθηγητή come before διάλεξη, like “the professor’s lecture” → η του καθηγητή διάλεξη?

Yes, η του καθηγητή διάλεξη is grammatically correct, but:

it sounds more formal, written, or literary,
it’s less common in everyday speech.

Normal, neutral order in spoken Greek is:

η διάλεξη του καθηγητή

The alternative:

η του καθηγητή διάλεξη

puts more emphasis on “του καθηγητή” (it’s specifically his lecture) and is the kind of structure you might see more in formal writing or stylistic/poetic language.

Why is του καθηγητή and not τον καθηγητή or ο καθηγητής?

These are different cases of the noun καθηγητής (professor):

ο καθηγητής – nominative (subject)
τον καθηγητή – accusative (direct object)
του καθηγητή – genitive (possession / “of the professor”)

In η διάλεξη του καθηγητή, we need the genitive, because it expresses whose lecture it is:

του καθηγητή = “of the professor”

So:

ο καθηγητής μιλάει. – “The professor is speaking.” (subject, nominative)
βλέπω τον καθηγητή. – “I see the professor.” (object, accusative)
η διάλεξη του καθηγητή. – “The professor’s lecture.” (possession, genitive)

Why is there no εγώ in the sentence? How do we know it means “I sit / I am sitting”?

Greek is a pro‑drop language: subject pronouns (like εγώ, “I”) are often omitted because the verb ending already shows the subject.

κάθομαι – 1st person singular → “I sit / I am sitting”
περιμένω – 1st person singular → “I wait / I am waiting”

So:

Κάθομαι στο αμφιθέατρο και περιμένω…
clearly has subject “I” from the verb forms.

You can say Εγώ κάθομαι στο αμφιθέατρο…, but that usually adds emphasis:
“I am the one who is sitting in the amphitheater…”

Is περιμένω closer to “I wait” or “I am waiting”? Why is the same form used?

Περιμένω is the simple present form and can mean both:

“I wait” (general, habitual)
“I am waiting” (right now, at this moment)

Greek does not have a separate morphological continuous tense like English “I am waiting”. The present tense covers both meanings, and context decides:

Κάθε μέρα περιμένω το λεωφορείο.
“Every day I wait for the bus.” (habit)
Τώρα περιμένω να αρχίσει η διάλεξη.
“Now I am waiting for the lecture to start.” (right now)

In your sentence, the context “I’m sitting in the amphitheater” makes the immediate, ongoing meaning (“I am waiting”) obvious.

What does και do here? Is it linking two sentences or just two verbs?

In Κάθομαι στο αμφιθέατρο και περιμένω…, the conjunction και links two verbs that share the same (understood) subject:

(εγώ) κάθομαι – I am sitting
(εγώ) περιμένω – I am waiting

So it means:

“I am sitting in the amphitheater and (I am) waiting for the lecture to start.”

This is very common in Greek: και can connect words, phrases, or entire clauses. Here, it connects two present-tense actions happening at the same time, done by the same subject.

Could I say κάθομαι μέσα στο αμφιθέατρο instead of στο αμφιθέατρο? Is there a difference?

Yes, you can say:

Κάθομαι μέσα στο αμφιθέατρο…

The meaning is very close, but μέσα adds a nuance of “inside” or “inside the interior of”:

στο αμφιθέατρο – “in the amphitheater / lecture hall” (neutral, standard)
μέσα στο αμφιθέατρο – “inside the amphitheater” (slightly more explicit about being inside)

In practice, for places like rooms, buildings, lecture halls, speakers very often use just στο without μέσα, unless they want to contrast inside vs outside.