Μου αρέσει να περπατάω στην ακτή το βράδυ, όταν δεν έχει πολύ θόρυβο.

Not literally. Greek αρέσω / αρέσει works more like to please in English.

So:

• Μου = to me
• αρέσει = is pleasing

So Μου αρέσει... is literally closer to ...is pleasing to me.

That is why Greek says:

• Μου αρέσει η μουσική. = I like music.
• literally: Music is pleasing to me.

In your sentence, the thing that is pleasing to me is the action να περπατάω στην ακτή το βράδυ...

Because αρέσει agrees with the thing being liked.

Here, the thing being liked is the whole action:

• να περπατάω στην ακτή το βράδυ, όταν δεν έχει πολύ θόρυβο

Greek treats that whole action/clause as a single idea, so it takes singular αρέσει.

Compare:

• Μου αρέσει να διαβάζω. = I like reading.
• Μου αρέσουν τα βιβλία. = I like books.

In the second example, τα βιβλία is plural, so Greek uses αρέσουν.

Modern Greek does not use an infinitive the way English does. Instead, it usually uses:

• να + finite verb

So where English says:

• I like to walk

Greek says:

• Μου αρέσει να περπατάω

Here να περπατάω means something like to walk / walking depending on the context.

After verbs like μου αρέσει, θέλω, μπορώ, πρέπει, this να structure is very common.

Examples:

• Θέλω να φύγω. = I want to leave.
• Μπορώ να έρθω; = Can I come?
• Μου αρέσει να μαγειρεύω. = I like cooking / to cook.

Yes, they mean the same thing: I walk / I am walking.

• περπατάω is very common in everyday speech
• περπατώ is also correct, and can sound a bit shorter or slightly more formal/literary depending on context

So these are both fine:

• Μου αρέσει να περπατάω στην ακτή.
• Μου αρέσει να περπατώ στην ακτή.

A learner will hear both forms.

στην is a contraction of:

• σε + την = στην

So:

• σε την ακτή becomes στην ακτή

This means on/to/at the coast/shore, depending on context.

Also, after σε, Greek uses the accusative case. That is why the noun phrase is in the accusative:

• nominative: η ακτή
• accusative: την ακτή

The noun ακτή itself looks the same in nominative and accusative singular, but the article changes:

• η ακτή
• την ακτή

Greek often uses the definite article in expressions of time.

So:

• το βράδυ = at night / in the evening
• το πρωί = in the morning
• το απόγευμα = in the afternoon

This is very natural Greek.

Also, this is an accusative time expression. Greek often uses the accusative to express when something happens.

So in your sentence:

• το βράδυ = at night / in the evening

It can be understood as either when or whenever, depending on context.

In this sentence:

• όταν δεν έχει πολύ θόρυβο

it means something like:

• when there isn’t much noise
• or whenever it isn’t very noisy

Because the sentence describes a general preference, English might naturally interpret it as whenever even though Greek uses όταν.

So the idea is: I like walking on the coast at night, especially when it’s quiet / when there isn’t much noise.

Yes, literally it looks like it doesn’t have much noise, but in Greek έχει is often used impersonally to mean:

• there is / there are

So:

• Έχει κόσμο. = There are people / It’s crowded.
• Δεν έχει κίνηση. = There isn’t traffic.
• Δεν έχει πολύ θόρυβο. = There isn’t much noise.

This is very natural colloquial Greek.

So here έχει does not mean that some specific subject has noise. It is more like an existential expression: there is noise.

Because πολύς changes form depending on gender, number, and case.

The noun θόρυβος is:

• masculine
• singular
• accusative here: θόρυβο

So the correct matching form is:

• πολύ θόρυβο

This means much noise.

A quick comparison:

• πολλή φασαρία = much noise / a lot of noise
  (φασαρία is feminine)
• πολύ νερό = much water
  (νερό is neuter)
• πολύ θόρυβο = much noise
  (θόρυβος is masculine)

So the form depends on the noun that follows.

Greek often leaves subject pronouns out when they are not needed.

English usually says:

• I like...

Greek usually just says:

• Μου αρέσει...

The idea of me / to me is already shown by μου, so there is no need to add εγώ.

If you want emphasis or contrast, you can add it:

• Εμένα μου αρέσει να περπατάω στην ακτή... = As for me, I like walking on the coast...

But in a neutral sentence, leaving it out is more natural.

Yes. In English, after I like, you can often use either:

• to walk
• walking

Greek uses the same να + verb structure for both ideas.

So:

• Μου αρέσει να περπατάω.

can be translated as either:

• I like to walk
• I like walking

The exact English version depends on what sounds most natural in context, not on a strict grammar difference in Greek.

Literally, ακτή means coast, shore, or seashore depending on context. So στην ακτή can be translated in a few natural ways in English.

Possible translations include:

• on the coast
• by the shore
• along the shore
• sometimes even on the beach, depending on the situation

The exact English choice depends on the image you want. Greek ακτή is a little broader than one single English word.

So a learner should understand the Greek as referring to the seaside/coastline area, not necessarily one exact English term.