Όταν γυρίζω από την παραλία, βγάζω το βρεγμένο μαγιό, πλένω τα σανδάλια και αφήνω τα γυαλιά ηλίου πάνω στο τραπέζι.

Because the sentence describes a habit or routine. In Greek, just like in English, the present tense is used for things you do regularly:

Όταν γυρίζω από την παραλία, βγάζω..., πλένω..., αφήνω...

This means something like Whenever I come back from the beach, I take off..., wash..., and leave...

If you were talking about one future occasion, Greek would usually change the form:

Όταν γυρίσω από την παραλία, θα βγάλω...

So γυρίζω here is not about right now; it is about repeated action.

Greek often leaves out subject pronouns because the verb ending already shows the person.

Here, all the verbs are first person singular:

• γυρίζω = I return / I come back
• βγάζω = I take off
• πλένω = I wash
• αφήνω = I leave

So εγώ is not necessary. You would add it only for emphasis or contrast:

Εγώ βγάζω το μαγιό, όχι αυτός.
I take off the swimsuit, not him.

Όταν means when or whenever. It introduces a time clause.

So:

Όταν γυρίζω από την παραλία
= When / Whenever I come back from the beach

In this sentence, it sets the time frame first, and then the main actions follow.

In Modern Greek, από is followed by the accusative.

So:

• η παραλία = the beach, subject form
• την παραλία = the beach, after από

Since παραλία is feminine singular, the article becomes την.

Because Όταν γυρίζω από την παραλία is an introductory subordinate clause, and the main clause comes after it.

So Greek normally writes:

Όταν γυρίζω από την παραλία, βγάζω...

This is very similar to English:

When I get back from the beach, I take off...

Greek uses the definite article more often than English.

In this sentence, the nouns are all presented as specific, known things:

• την παραλία
• το βρεγμένο μαγιό
• τα σανδάλια
• τα γυαλιά ηλίου
• το τραπέζι

In English, you might sometimes leave the out or use my instead, but Greek very naturally keeps the article.

Because Greek often omits the possessive when it is obvious from context, especially with clothes, body parts, and personal items.

So:

βγάζω το βρεγμένο μαγιό
naturally means
I take off my wet swimsuit

If you want to state ownership clearly, you can say:

βγάζω το βρεγμένο μαγιό μου

But in ordinary speech, leaving out μου is completely natural here.

Because the adjective must agree with the noun in gender, number, and case.

• μαγιό is neuter singular
• so the adjective is also neuter singular: βρεγμένο

That is why you get:

το βρεγμένο μαγιό

If the noun were different, the adjective would change too.

Μαγιό is treated as a neuter noun in Greek, so it takes το and neuter adjective forms:

• το μαγιό
• το βρεγμένο μαγιό

It is also a word that does not change much in form, so the article and adjective help show its grammar.

Because Greek normally talks about sandals as a pair, just like English often does.

• το σανδάλι = one sandal
• τα σανδάλια = sandals

So in this sentence, πλένω τα σανδάλια means I wash the sandals / my sandals.

Γυαλιά ηλίου is the standard Greek expression for sunglasses.

Literally, it is something like:

• γυαλιά = glasses
• ηλίου = of the sun

So ηλίου is the genitive singular of ήλιος.

This kind of structure is very common in Greek. Even though the literal breakdown is glasses of sun, you should learn γυαλιά ηλίου as one normal expression meaning sunglasses.

Στο is a contraction of:

σε + το = στο

So:

• σε το τραπέζι becomes στο τραπέζι

And πάνω στο τραπέζι means:

• on the table
• more literally, on top of the table

This is a very common Greek way to express location.

Yes. Greek word order is more flexible than English word order.

The sentence as given is a neutral, natural order for describing a sequence of actions:

βγάζω το βρεγμένο μαγιό, πλένω τα σανδάλια και αφήνω τα γυαλιά ηλίου πάνω στο τραπέζι

But Greek can move things around for emphasis. For example:

Τα γυαλιά ηλίου τα αφήνω πάνω στο τραπέζι.

This puts extra focus on the sunglasses.

So the given order is not the only possible order, but it is a very normal one.

Both can mean return / come back, but γυρίζω is often more everyday and conversational.

So:

• γυρίζω από την παραλία = I come back from the beach
• επιστρέφω από την παραλία = I return from the beach

The second one is also correct, but it can sound a little more formal or neutral depending on context. In a sentence about daily routine, γυρίζω sounds very natural.