Το κομπόστ είναι στο μπαλκόνι.

Το is the neuter singular definite article, meaning the.

Greek uses definite articles much more often than English does. So where English might sometimes just say compost, Greek often says the compost: το κομπόστ.

Here, κομπόστ is treated as a neuter singular noun, so it takes το.

Κομπόστ is a loanword (borrowed from another language), and in everyday Modern Greek it is commonly treated as an indeclinable or only minimally changing noun.

In this sentence, you can think of it simply as a neuter noun used with το:

• το κομπόστ

For a learner, the important thing is that you will usually meet it in this fixed form.

Είναι means is / are and comes from the verb είμαι (to be).

In this sentence, είναι is the 3rd person singular present form, so it matches το κομπόστ = it.

So:

• το κομπόστ είναι = the compost is

A useful thing to remember is that είναι is also used for they are, so the same form can mean is or are depending on the subject.

Στο is a contraction of:

• σε = in / on / at / to
• το = the

So:

• σε το → στο

This contraction is the normal form in standard Greek. So instead of writing σε το μπαλκόνι, Greek normally writes στο μπαλκόνι.

Greek σε is broader than English prepositions. It can correspond to in, on, at, or sometimes to, depending on context.

So στο μπαλκόνι literally uses σε, but in natural English the best translation is often:

• on the balcony

That does not mean Greek is using a special word for on here. It is just that σε + article covers several location meanings.

Because μπαλκόνι is also a neuter singular noun.

So:

• το μπαλκόνι = the balcony

When το combines with σε, it becomes στο, which is why you see:

• στο μπαλκόνι

After σε, Greek normally uses the accusative case.

So in grammatical terms:

• το κομπόστ = subject, nominative
• στο μπαλκόνι = prepositional phrase with σε
  • accusative

However, for neuter singular nouns like κομπόστ and μπαλκόνι, the nominative and accusative forms are often identical in shape. So you do not see a visible change here.

No. Greek word order is more flexible than English word order.

Το κομπόστ είναι στο μπαλκόνι is the most neutral, straightforward order:

• subject + verb + location

But Greek could also say things like:

• Στο μπαλκόνι είναι το κομπόστ

That might sound more marked, depending on context, with extra focus on where it is.

So the given sentence is the standard, neutral way to say it.

No. Greek usually does not need an explicit subject pronoun when the subject is already clear.

Here the subject is the noun phrase:

• Το κομπόστ

So there is no need to add a separate Greek word for it.

This is very normal in Greek. Subject pronouns are often omitted unless there is emphasis or contrast.

In Modern Greek, μπ is commonly used to represent a b sound.

So:

• μπαλκόνι is pronounced roughly like bal-KO-nee
• κομπόστ is pronounced roughly like kom-BOST or ko-BOST, depending on speaker and style

A simple learner-friendly approximation is:

• Το κομπόστ είναι στο μπαλκόνι
• to kom-BOST EE-ne sto bal-KO-nee

Greek accent marks show which syllable is stressed.

In this sentence:

• κομπόστ → stress on the last syllable
• είναι → stress on the first syllable
• μπαλκόνι → stress on -κό-

These marks are important in writing and help you pronounce words correctly.

Normally, no. That would sound unnatural in ordinary Greek.

Greek usually wants the definite article with nouns in this kind of sentence:

• Το κομπόστ είναι στο μπαλκόνι

Leaving out το would only happen in special contexts, headings, labels, or unusual speech. For normal everyday Greek, keep the articles.