Το βασιλικό στο μπαλκόνι θέλει λίγο νερό κάθε βράδυ.

Yes, βασιλικός / βασιλική / βασιλικό can be an adjective meaning royal. But in this sentence, το βασιλικό is a noun and means the basil plant.

Greek often uses adjective-shaped words as nouns when the meaning is understood. Here, the article το helps show that βασιλικό is being used as a noun.

So in this sentence:

• το βασιλικό = the basil
• not the royal one

Greek uses the definite article much more often than English does.

Here το βασιλικό refers to a specific basil plant, and στο μπαλκόνι identifies which one: the one on the balcony.

So the article is natural because the speaker has a particular plant in mind:

• το βασιλικό στο μπαλκόνι = the basil on the balcony

If you removed το, the sentence would sound less natural in this context.

Because the noun βασιλικό meaning basil is neuter.

Greek nouns have grammatical gender, and this one is neuter:

• το βασιλικό

If it were masculine, it would be ο βασιλικός, but that is not the normal noun for the plant.

So the ending -ό matches the neuter article το.

στο is a contraction of σε + το.

So:

• σε το → στο

In this sentence:

• στο μπαλκόνι = on the balcony or at the balcony, depending on context
• here the natural English translation is on the balcony

This contraction is extremely common in everyday Greek.

In Modern Greek, the preposition σε normally takes the accusative case.

So στο μπαλκόνι contains:

• σε + το
• noun in the accusative

But μπαλκόνι is a neuter noun, and in the singular the nominative and accusative forms are the same:

• nominative: το μπαλκόνι
• accusative: το μπαλκόνι

So you do not see a visible change in the noun form, even though the case is accusative.

It most naturally describes the basil.

So the structure is:

• Το βασιλικό στο μπαλκόνι = The basil on the balcony
• θέλει λίγο νερό κάθε βράδυ = needs a little water every night

In other words, στο μπαλκόνι identifies which basil plant we are talking about.

Greek word order is flexible, but here the placement strongly suggests that στο μπαλκόνι belongs with το βασιλικό.

Yes, θέλω literally means to want, but in everyday Greek it is also very commonly used in the sense of to need or to require, especially with things like plants, food, repairs, time, and effort.

So:

• Το βασιλικό θέλει λίγο νερό = The basil needs a little water

This is a very natural Greek way to say it.

You could also say:

• χρειάζεται λίγο νερό

That is also correct, but θέλει sounds very everyday and idiomatic here.

Because the subject is το βασιλικό, which is third person singular.

The verb θέλω in the present tense goes like this:

• εγώ θέλω
• εσύ θέλεις
• αυτό/αυτή/αυτό θέλει
• εμείς θέλουμε
• εσείς θέλετε
• αυτοί/αυτές/αυτά θέλουν

Since το βασιλικό is singular, the correct form is θέλει.

Because νερό is being used as an uncountable noun, and λίγο means a little or some.

So:

• λίγο νερό = a little water

You do not need an article here, just as in English you usually say a little water, not a little the water.

Also, λίγο is in its neuter form, matching νερό, which is neuter:

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

It is in the accusative case because it is the direct object of θέλει.

The basil is the thing that needs, and the water is the thing needed.

So:

• subject: Το βασιλικό
• verb: θέλει
• direct object: λίγο νερό

Again, because νερό is neuter singular, its nominative and accusative forms are the same:

• το νερό
• το νερό

So the case is accusative, even though the form does not change.

Because κάθε means each or every, and in Greek it is normally followed by a singular noun.

So:

• κάθε βράδυ = every night / every evening

This is different from English, where learners sometimes expect a plural idea because the meaning is repeated time. Greek does not do that here.

Also, κάθε does not change form:

• κάθε μέρα
• κάθε νύχτα
• κάθε βράδυ

It can overlap with both, depending on context.

βράδυ usually refers to the evening/night period after daytime. In many sentences like this one, English may translate it as every night, but every evening can also be possible depending on the situation.

So the Greek word is a little broader than a single exact English equivalent.

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

The given sentence is a very natural neutral order:

• Το βασιλικό στο μπαλκόνι θέλει λίγο νερό κάθε βράδυ.

But you could also say:

• Κάθε βράδυ το βασιλικό στο μπαλκόνι θέλει λίγο νερό.
• Το βασιλικό στο μπαλκόνι κάθε βράδυ θέλει λίγο νερό.

The basic meaning stays the same, but the emphasis changes slightly:

• putting κάθε βράδυ first emphasizes the time
• keeping it at the end sounds neutral and smooth

At the beginning of a word, μπ is usually pronounced like b.

So μπαλκόνι sounds roughly like:

• bal-KO-ni

The stress is on κό.

More generally in this sentence, the stressed syllables are:

• βασιλικό
• μπαλκόνι
• νερό
• βράδυ

Paying attention to the written accent marks is very important in Greek pronunciation.