Στο παρτέρι έχει λουλούδια, βασιλικό και λίγο θυμάρι.

Στο is the contracted form of σε το.

• σε = in / at / on / to
• το = the for a neuter singular noun

So στο παρτέρι means in the flower bed.

Also, σε takes the accusative case. Here παρτέρι is accusative, but because it is a neuter noun, the nominative and accusative singular look the same.

Greek word order is more flexible than English word order. Putting Στο παρτέρι first sets the scene first:

In the flower bed, ...

That is very natural in Greek. It makes the flower bed the topic, and then the sentence tells you what is there.

English needs a dummy subject in sentences like there is or there are. Greek usually does not.

So instead of literally saying there is flowers, Greek can simply say:

• έχει λουλούδια
• υπάρχουν λουλούδια

Both can mean there are flowers, depending on style.

In everyday Greek, έχει is often used impersonally to mean there is / there are.

In this use, it normally stays in the 3rd person singular form έχει, even if what follows is plural.

So:

• Στο παρτέρι έχει λουλούδια = There are flowers in the flower bed

This is very common in spoken Greek.

Because the sentence is introducing non-specific things that are present in the flower bed.

Greek often omits the article in this kind of existential sentence, especially with έχει. So the sense is:

• flowers
• basil
• a little thyme

In natural English, you might translate that as some flowers, basil, and a little thyme.

If you added articles, the meaning would usually become more specific.

Because βασιλικός is the dictionary form (nominative singular), but after έχει it behaves like a direct object, so it goes into the accusative.

So:

• ο βασιλικός = nominative
• βασιλικό = accusative

This is a useful clue that, in this sentence, the listed things are being treated grammatically as objects of έχει.

Yes.

After existential έχει, the things that exist are usually treated as objects, so they appear in the accusative.

In this sentence:

• λουλούδια = accusative plural, but it looks the same as nominative because it is neuter
• βασιλικό = clearly accusative singular of βασιλικός
• θυμάρι = accusative singular, but again it looks the same as nominative because it is neuter

So only βασιλικό shows an obvious case change.

Λίγο means a little or some.

Here θυμάρι is being treated as an uncountable herb, not as separate countable plants. So λίγο θυμάρι means:

a little thyme / some thyme

Also, λίγο is neuter singular, which matches θυμάρι, also neuter singular.

If you wanted to count separate thyme plants or units, Greek would use a different structure.

Yes. A more formal or more neutral version would be:

Στο παρτέρι υπάρχουν λουλούδια, βασιλικός και λίγο θυμάρι.

That also means There are flowers, basil, and a little thyme in the flower bed.

The important difference is grammatical:

• with έχει, the nouns are treated like objects, so you get βασιλικό
• with υπάρχουν, the nouns are subjects, so you get βασιλικός

So the original sentence sounds very natural in everyday spoken Greek, while υπάρχουν sounds a bit more careful or formal.