Learn Hardcore Greek: Στο πάνω ράφι βάζω τα βιβλία μου, ενώ στο κάτω ράφι βάζω τα παλιά μου τετράδια. - On the top shelf I put my books, while on the bottom shelf I put my old notebooks.

στο πάνω ράφι = literally “on the upper shelf”, with πάνω behaving like an adjective that characterizes the shelf. This is the normal, neutral way to say “the top shelf / the higher shelf”.
στο ράφι πάνω = more like “on the shelf up there” (a bit more adverbial, pointing to location). It’s understandable but less standard in this context, and sounds more like spoken, slightly “pointing” language.

In your sentence, we’re contrasting the upper shelf with the lower shelf, so Greek prefers:

στο πάνω ράφι … στο κάτω ράφι
two parallel noun phrases, each with an adjective-like word (πάνω, κάτω) coming before the noun.

Is πάνω an adjective here? Does it change form for gender or number?

Historically πάνω is an adverb (“up, above”), but in phrases like το πάνω ράφι it behaves like an invariable adjective (it acts like an adjective but doesn’t change form).

So you will see:

το πάνω ράφι – the upper shelf (neuter singular)
τα πάνω ράφια – the upper shelves (neuter plural)
η πάνω σειρά – the upper row (feminine)
ο πάνω όροφος – the upper floor (masculine)

In all these, πάνω stays the same; it doesn’t change ending for gender or number. The article and the noun carry the grammatical information; πάνω just adds the meaning “upper / above”. The same is true for κάτω.

What gender and case is ράφι, and how can I tell?

ράφι (shelf) is:

gender: neuter
number: singular
case: accusative

You can tell from:

The article: στο = σε + το (neuter singular accusative).
The role in the sentence: it’s the object of the preposition σε, and Greek uses the accusative after σε.

The basic forms of ράφι are:

το ράφι – the shelf (nominative/accusative singular)
του ραφιού – of the shelf (genitive singular)
τα ράφια – the shelves (nominative/accusative plural)
των ραφιών – of the shelves (genitive plural)

Why is βάζω in the present tense here? Does it mean “I am putting” or “I put”?

Greek present tense βάζω can cover both:

I am putting (right now, progressive)
I put / I usually put (habitual, repeated action)

In this sentence, because we’re describing a general habit or rule (“this is how I organize my shelves”), βάζω means:

I put / I keep my books on the top shelf,
while on the bottom shelf I put / keep my old notebooks.

Greek doesn’t need a separate “simple present” vs “present continuous” form like English. Context tells you whether it’s “I am putting” right now or “I (generally) put”.

Where is the subject “I” in Greek? Why is εγώ missing?

In Greek, the personal subject pronoun (like εγώ = I) is usually dropped unless you want to emphasize it.

The verb ending in βάζω already tells you the subject:

βάζω = I put
βάζεις = you (singular) put
βάζει = he/she/it puts
βάζουμε = we put
βάζετε = you (plural/polite) put
βάζουν(ε) = they put

So:

(Εγώ) βάζω τα βιβλία μου…
The εγώ is understood from -ω, so it’s normally left out:

Στο πάνω ράφι βάζω τα βιβλία μου…

If you say Εγώ βάζω τα βιβλία μου…, you’re stressing I, as in “I put my books there (not someone else)”.

Why is it τα βιβλία μου but τα παλιά μου τετράδια? Where does μου go with adjectives?

The possessive μου is an unstressed clitic pronoun and normally comes after the noun phrase it belongs to, but inside that phrase it has some flexibility.

Without an adjective:

τα βιβλία μου = my books
(article + noun + possessive)

With an adjective, a very common word order is:

τα παλιά μου τετράδια = my old notebooks
(article + adjective + possessive + noun)

Other natural possibilities:

τα παλιά τετράδιά μου (article + adjective + noun + possessive) – also common
τα τετράδιά μου τα παλιά – “my notebooks, the old ones” (more contrastive/emphatic)

What you don’t say is something like τα μου παλιά τετράδια; the clitic μου never precedes the article or stand alone before the noun phrase.

So, τα παλιά μου τετράδια is a very standard, everyday pattern.

What exactly does ενώ mean here? How is it different from just using και?

ενώ is a conjunction that often means:

while / whereas / whereas on the other hand

It introduces something that contrasts with or is different from what came before.

In your sentence:

Στο πάνω ράφι βάζω τα βιβλία μου, ενώ στο κάτω ράφι βάζω τα παλιά μου τετράδια.

The ενώ highlights a contrast:

on the top shelf: books
on the bottom shelf: old notebooks

If you used και instead:

…και στο κάτω ράφι βάζω τα παλιά μου τετράδια.

that would sound more like simply adding another fact (“and on the bottom shelf I put…”), without underlining the nice symmetrical contrast. Both are grammatical, but ενώ is better for this “up vs down” opposition.

Why is βάζω repeated in the second part? Could you say ενώ στο κάτω τα παλιά μου τετράδια and drop the verb?

You can omit the verb in the second clause in Greek if the meaning is clear from the first verb. For example, people do say:

Στο πάνω ράφι βάζω τα βιβλία μου, ενώ στο κάτω (ράφι) τα παλιά μου τετράδια.

Here βάζω is understood in the second clause and left out for brevity.

However, in careful or neutral style, especially in “textbook” sentences, we often repeat the verb:

…στο κάτω ράφι βάζω τα παλιά μου τετράδια.

Repeating βάζω makes the sentence very clear and nicely parallel in structure:

στο πάνω ράφι βάζω… ενώ στο κάτω ράφι βάζω…

Your version ενώ στο κάτω τα παλιά μου τετράδια is understandable but slightly clipped; adding ράφι or βάζω (or both) makes it more natural:

…ενώ στο κάτω ράφι τα παλιά μου τετράδια. (elliptical but ok in speech)
…ενώ στο κάτω βάζω τα παλιά μου τετράδια. (also acceptable)
…ενώ στο κάτω ράφι βάζω τα παλιά μου τετράδια. (fully explicit, textbook-like)

Are παλιά and παλαιά the same word? Which one should I use?

Yes, παλιά and παλαιά come from the same root and both mean “old”, but in modern Greek they differ in style:

παλιά – the normal, everyday form in spoken and written modern Greek.
παλαιά – more formal, old-fashioned, or used in set phrases and in more “learned” or official language.

In your sentence, the natural modern choice is:

τα παλιά μου τετράδια

If you wrote τα παλαιά μου τετράδια, it wouldn’t be wrong, but it would sound more formal or bookish.

Why is there a comma before ενώ?

The sentence contains two clauses, each with its own verb βάζω:

Στο πάνω ράφι βάζω τα βιβλία μου,
ενώ στο κάτω ράφι βάζω τα παλιά μου τετράδια.

Greek punctuation normally uses a comma before conjunctions like ενώ, αλλά, όμως when they introduce a clause that contrasts with or adds to the previous one.

So the comma:

marks the end of the first clause, and
signals that ενώ is now introducing a second, contrasting clause.

You don’t put a comma after ενώ here; only before it.

Why do βιβλία and τετράδια have the article τα? In English we’d probably say “I put my books” and “my old notebooks” without “the”.

In Greek, the definite article is used more often than in English, especially with possessives.

Patterns like:

τα βιβλία μου – literally “the books of mine”
τα παλιά μου τετράδια – “the old notebooks of mine”

are the normal way to say “my books / my old notebooks”.

Key points:

A possessive pronoun (μου, σου, του, της, μας, σας, τους) almost always appears together with the definite article.
Greek doesn’t have an indefinite article in the plural (“some”), so “some books” is often just βιβλία or κάποια βιβλία. But with μου, you almost always use τα:
- βιβλία = books (in general, no possessive)
- τα βιβλία μου = my books

So τα βιβλία μου is the natural Greek equivalent of “my books”.

Could I change the word order, like Τα βιβλία μου τα βάζω στο πάνω ράφι? Would it still be correct?

Yes, Greek word order is quite flexible, and your version is grammatical, but it changes the emphasis.

Original:

Στο πάνω ράφι βάζω τα βιβλία μου, ενώ στο κάτω ράφι βάζω τα παλιά μου τετράδια.
→ focus on where things go (on the top shelf / on the bottom shelf).

Alternative:

Τα βιβλία μου τα βάζω στο πάνω ράφι, ενώ τα παλιά μου τετράδια (τα) βάζω στο κάτω ράφι.
→ now you put more emphasis on what you do with my books / my old notebooks (“My books I put on the top shelf, while my old notebooks I put on the bottom shelf”).

Some common, natural variants:

Τα βιβλία μου τα βάζω στο πάνω ράφι, ενώ τα παλιά μου τετράδια στο κάτω.
Βάζω τα βιβλία μου στο πάνω ράφι, ενώ στο κάτω βάζω τα παλιά μου τετράδια.

They’re all correct; the differences are mainly about focus and style, not grammar.