Learn Hardcore Greek: Κάθομαι πάνω στο χαλί και διαβάζω ελληνικά.

Κάθομαι ends in -μαι, which here marks 1st person singular (I).
So Κάθομαι on its own already means “I sit / I am sitting.”
You would only add εγώ for emphasis:
Εγώ κάθομαι πάνω στο χαλί… = I am the one sitting on the carpet…

What kind of verb is κάθομαι, and why does it end in -ομαι?

Κάθομαι is a verb that only appears in the middle/passive form in modern Greek. There is no common active form like *κάθω.

Verbs ending in -ομαι in the present tense are middle/passive in form, but many of them have active meaning, like:

κάθομαι = I sit / I am sitting
θυμάμαι = I remember
κοιμάμαι = I sleep

So κάθομαι is just the normal way to say “I sit / I’m sitting”; the -ομαι is part of its regular conjugation, not a separate reflexive pronoun.

What’s the difference between κάθομαι and να κάτσω, which I sometimes see?

They express different aspects (types of action):

κάθομαι (present, imperfective): a state or ongoing action
- Κάθομαι στο χαλί. = I am (sitting) on the carpet.
να κάτσω (aorist subjunctive): a single act of sitting down
- Θέλω να κάτσω. = I want to sit down.

So κάθομαι = “I am in a sitting position” / “I sit (habitually)”,
while να κάτσω is about the moment of moving into that sitting position.

How does πάνω στο work? Is it one word or a combination of words?

It’s a combination:

πάνω = on (top), above
σε = in, at, on (preposition)
το = the (neuter singular article)

In everyday speech and writing, σε + το contracts to στο.
So:

πάνω στο χαλί = πάνω σε το χαλί = on (top of) the carpet.

You can also see επάνω instead of πάνω; it’s just a slightly more formal or full version.

Why is χαλί in the accusative after στο if it’s just a place, not a direct object?

In modern Greek, most prepositions (including σε) are followed by the accusative case, even for simple location.

σε + accusative is standard: στο σπίτι, στη δουλειά, στο χαλί.

Χαλί is a neuter noun, and its nominative and accusative singular look the same (χαλί). The case is actually shown by the article το → στο. So grammatically it’s accusative, but that’s just the normal pattern after σε for “in/at/on”.

Why is it στο χαλί and not στον χαλί or στη χαλί?

Because χαλί is a neuter noun in Greek.

Masculine: ο (στον)
Feminine: η (στη)
Neuter: το (στο)

Since χαλί is neuter (το χαλί = the carpet), the correct contracted form with σε is:

σε + το χαλί → στο χαλί

Could I just say Κάθομαι στο χαλί without πάνω?

Yes.

Κάθομαι στο χαλί is perfectly natural and usually understood as “I’m sitting on the carpet.”
Κάθομαι πάνω στο χαλί emphasizes “on top of” the carpet a bit more, or can add clarity when the location could otherwise be ambiguous.

In many everyday contexts, πάνω is optional and can be left out without changing the meaning much.

Can I change the word order, for example Διαβάζω ελληνικά και κάθομαι πάνω στο χαλί?

Yes. Greek word order is fairly flexible.

Κάθομαι πάνω στο χαλί και διαβάζω ελληνικά.
Διαβάζω ελληνικά και κάθομαι πάνω στο χαλί.

Both are grammatical and natural. The difference is only in what you mention first / emphasize slightly. The original puts a tiny bit more focus on the sitting, the alternative on the reading, but in normal conversation they feel almost the same.

Why is ελληνικά in the neuter plural? Isn’t Greek an adjective?

Ελληνικά is originally an adjective: it’s the neuter plural of ελληνικός, -ή, -ό (Greek).

Greek often uses neuter plural adjectives as nouns, especially for languages:

(τα) ελληνικά = Greek (language)
(τα) αγγλικά = English
(τα) γαλλικά = French

In διαβάζω ελληνικά, the noun “language” (e.g. η γλώσσα) is understood and left out. Literally it’s like saying “I read Greek (things)” or “I read in Greek.”

Why is there no article before ελληνικά? Could I say τα ελληνικά?

After verbs like μιλάω, διαβάζω, γράφω, μαθαίνω used with languages, Greek usually omits the article:

Διαβάζω ελληνικά.
Μιλάω ελληνικά.
Μαθαίνω ελληνικά.

You can use τα ελληνικά in other contexts, typically when treating the language as a more definite, “thing-like” noun:

Τα ελληνικά είναι δύσκολα. = Greek (the language) is difficult.
Κάνω λάθη στα ελληνικά. = I make mistakes in Greek.

But in your sentence, Διαβάζω ελληνικά (no article) is the most natural choice.

Does διαβάζω mean only “to read”, or can it also mean “to study”?

Διαβάζω covers both meanings, depending on context:

διαβάζω ένα βιβλίο = I’m reading a book.
διαβάζω για τις εξετάσεις = I’m studying for the exams.

In διαβάζω ελληνικά, it can mean either:

reading texts in Greek, or
studying Greek as a language.

Often the broader idea is “I’m working with/learning Greek.”

How do I know if the Greek present here means “I sit and read” or “I am sitting and reading”?

Modern Greek has one present tense (παροντικός) that covers both:

habitual / general: I sit, I read
progressive / right now: I am sitting, I am reading

So Κάθομαι πάνω στο χαλί και διαβάζω ελληνικά can translate as either:

“I sit on the carpet and read Greek.”
“I am sitting on the carpet and reading Greek.”

English must choose a form; Greek leaves it to context (time expressions, situation) to make it clear.

Why is ελληνικά not capitalized in Greek, while “Greek” is capitalized in English?

In Greek, adjectives are not capitalized, and the words for languages are adjectives used as nouns. So:

ελληνικά, αγγλικά, γαλλικά are normally lowercase, unless they begin a sentence or are part of a proper name.

English, by contrast, capitalizes nationalities and language names (Greek, English, French), so “Greek” is capitalized but ελληνικά is not.