Στο τέλος της μέρας κάθομαι στο μπαλκόνι με λίγη λιακάδα ακόμα, κοιτάω τα κοχύλια που μάζεψα και σκέφτομαι ότι προτιμώ τέτοιες ήσυχες ώρες παρά να έχει παντού πολύ κόσμο.

Στο is the contraction of σε το, meaning at/in the.

το τέλος means the end, and after τέλος Greek normally uses the genitive for what something is the end of:

• το τέλος της μέρας = the end of the day

So:

• Στο τέλος της μέρας = At the end of the day

This is a very common structure:

• στην αρχή του μήνα = at the beginning of the month
• στο τέλος της εβδομάδας = at the end of the week

Both are correct.

• η μέρα is the common everyday form
• η ημέρα is the more formal/full form

So:

• στο τέλος της μέρας sounds natural and conversational
• στο τέλος της ημέρας sounds a bit more formal or careful

The meaning is the same.

It can mean both, depending on context.

Greek present tense often covers both:

• I sit
• I am sitting

So κάθομαι στο μπαλκόνι can mean:

• I sit on the balcony
• I’m sitting on the balcony

In this sentence, because it describes a scene happening at the end of the day, English would usually translate it as I sit or I’m sitting depending on style.

Also note:

• κάθομαι = I sit / I am seated / I am sitting
• κάθομαι να... can also mean I settle down to... in other contexts

Again, στο is σε + το.

• το μπαλκόνι = the balcony
• στο μπαλκόνι = on the balcony / at the balcony

Greek often uses σε + article where English uses on, in, or at, depending on the noun and context.

So you should not expect a one-to-one match with English prepositions:

• στο σπίτι = at home / in the house
• στο τραπέζι = on the table
• στο μπαλκόνι = on the balcony

Literally, it is something like:

• με = with
• λίγη = a little
• λιακάδα = sunshine / sunny weather
• ακόμα = still / yet

So the phrase means:

• with a little sunshine still
• more naturally: while there is still a little sunshine left

This is not really saying the speaker is physically holding sunshine. με here helps describe the conditions of the scene.

A good natural understanding is:

• I sit on the balcony while there’s still a bit of sunshine

Because λιακάδα is a feminine singular noun.

So the adjective/quantifier has to agree with it:

• λίγος for masculine
• λίγη for feminine
• λίγο for neuter

Examples:

• λίγος χρόνος = a little time
• λίγη λιακάδα = a little sunshine
• λίγο νερό = a little water

Agreement is very important in Greek.

Yes. Both κοιτάω and κοιτάζω are common and mean I look at.

This is one of those verbs that can appear in more than one present-tense form in Modern Greek:

• κοιτάω
• κοιτάζω

Both are natural. The choice is often just a matter of preference, style, or habit.

So:

• κοιτάω τα κοχύλια
• κοιτάζω τα κοχύλια

Both mean I look at the shells.

κοχύλι is a neuter noun meaning shell or seashell.

Its plural is:

• το κοχύλι = the shell
• τα κοχύλια = the shells

Here τα κοχύλια is the direct object of κοιτάω:

• κοιτάω τα κοχύλια = I look at the shells

So:

• τα = neuter plural article
• κοχύλια = neuter plural noun

Here που means that / which and introduces a relative clause.

So:

• τα κοχύλια που μάζεψα = the shells that I collected

This is a very common use of που in Modern Greek. It often covers meanings that English expresses with that, who, or which.

Examples:

• ο φίλος που είδα = the friend that I saw
• το βιβλίο που αγόρασα = the book that I bought

So in your sentence:

• που μάζεψα = that I picked up / collected

Because the shells were collected before the moment of sitting and looking at them.

Greek is doing exactly what English often does:

• I sit on the balcony, look at the shells that I collected, and think...

The main scene is in the present:

• κάθομαι
• κοιτάω
• σκέφτομαι
• προτιμώ

But the collecting happened earlier, so Greek uses the aorist:

• μάζεψα = I collected / I picked up

The aorist here presents the action as a completed whole.

Yes, both are possible.

• ότι = that
• πως = that

So:

• σκέφτομαι ότι...
• σκέφτομαι πως...

Both mean I think that...

One useful note:

• ότι = that
• ό,τι = whatever / anything that

Those are different words, even though they look very similar. In your sentence it is ότι with the meaning that.

προτιμώ means I prefer.

Greek often expresses comparison after προτιμώ with παρά:

• προτιμώ καφέ παρά τσάι = I prefer coffee rather than tea

When the second part is a whole action or clause, Greek commonly uses:

• παρά να + subjunctive

So:

• προτιμώ τέτοιες ήσυχες ώρες παρά να έχει παντού πολύ κόσμο

means:

• I prefer such quiet hours rather than there being lots of people everywhere

In more natural English:

• I prefer quiet moments like these to there being crowds everywhere
• I prefer these quiet hours rather than having lots of people everywhere

You may also hear other structures in Greek, such as από το να, but παρά να is perfectly normal.

Because Greek does not always need an article where English uses one or where a learner expects one.

Here the phrase is indefinite/general:

• τέτοιες ήσυχες ώρες = such quiet hours / quiet moments like these

The word τέτοιες already helps define the noun phrase, so an article is not necessary.

Compare:

• προτιμώ τέτοιες ήσυχες ώρες = I prefer such quiet hours
• προτιμώ τις ήσυχες ώρες = I prefer the quiet hours or I like quiet hours in a more generic/article-based way

In this sentence, the article would sound less natural with τέτοιες.

Because ώρες is feminine plural.

The noun is:

• η ώρα = hour
• οι ώρες = hours

So anything modifying it must agree:

• τέτοιες = feminine plural
• ήσυχες = feminine plural
• ώρες = feminine plural

This gives:

• τέτοιες ήσυχες ώρες = such quiet hours

That is basic adjective agreement in Greek:

• gender
• number
• case

all have to match.

In everyday Greek, έχει is very often used in an impersonal/existential way, similar to English there is / there are.

So:

• έχει κόσμο εδώ = there are people here / it’s crowded here
• δεν έχει πολύ κόσμο = there aren’t many people / it isn’t very crowded

In your sentence:

• να έχει παντού πολύ κόσμο literally = for it to have a lot of people everywhere

But naturally it means:

• for there to be lots of people everywhere
• for everywhere to be crowded

This is a very common colloquial Greek pattern.

Because κόσμος can mean people as a collective noun.

So:

• πολύς κόσμος = a lot of people
• είδα πολύ κόσμο = I saw a lot of people

Even though the meaning is plural in English, Greek often uses singular κόσμος in this collective sense.

So:

• πολύ κόσμο does not mean much world here
• it means many people / a crowd / lots of people

You could say πολλούς ανθρώπους, but πολύ κόσμο is more natural in this kind of sentence.

παντού means everywhere.

In:

• να έχει παντού πολύ κόσμο

it modifies the whole situation:

• for there to be lots of people everywhere

Its position is flexible, but the sentence naturally places it before πολύ κόσμο:

• παντού πολύ κόσμο = lots of people everywhere

You could move it in some contexts, but this placement sounds very natural and clear.

Yes. The sentence mixes present tense and aorist in a very natural way.

Present tense for the current scene or general habit:

• κάθομαι
• κοιτάω
• σκέφτομαι
• προτιμώ

Aorist for the completed earlier action:

• μάζεψα

So the sentence creates a living present scene and inserts one finished past action inside it:

• I sit...
• I look...
• I think...
• at the shells I collected earlier

That contrast is very typical and useful in Greek narrative and description.