Στο παρτέρι μπροστά από το σπίτι έχει λουλούδια, βασιλικό και θυμάρι.

Yes. Στο is the contracted form of σε + το.

In Modern Greek, σε very commonly combines with the definite article:

• σε + το → στο
• σε + τη(ν) → στη(ν)
• σε + τα → στα

So στο παρτέρι means in the flowerbed or in the flower bed.

In standard Greek, σε το παρτέρι would sound unnatural; στο παρτέρι is the normal form.

Παρτέρι usually means a flowerbed, garden bed, or a planted area, often a small bordered patch of soil with flowers or herbs.

So here στο παρτέρι refers to the planted area in front of the house, not the whole garden.

Μπροστά από means in front of.

It works as a fixed expression:

• μπροστά = in front / ahead
• από introduces the reference point

So:

• μπροστά από το σπίτι = in front of the house

A native English speaker may want to translate word-for-word, but it is better to learn μπροστά από as one unit.

Yes, literally έχει means has, but in everyday Greek it is also very commonly used to mean there is or there are.

So:

• έχει λουλούδια can mean there are flowers
• έχει κόσμο εδώ means there are people here
• έχει πρόβλημα means there is a problem

In this sentence, έχει is being used in that everyday existential sense, not in the sense of someone possessing something.

A more formal or textbook-like alternative would be υπάρχουν:

• Στο παρτέρι μπροστά από το σπίτι υπάρχουν λουλούδια...

But έχει is very natural in spoken Greek.

Because this έχει is functioning impersonally, almost like a fixed expression meaning there is/there are.

It does not agree in number with the noun that follows it the way English is/are does.

So Greek speakers can say:

• Έχει ένα δέντρο. = There is one tree.
• Έχει δύο δέντρα. = There are two trees.

That is very common in everyday speech.

There is no real subject in the normal English sense.

English needs a dummy subject, there, in sentences like there are flowers. Greek does not need that here. It can simply say έχει λουλούδια.

So this is one of those places where Greek and English build the sentence differently:

• English: There are flowers
• Greek: Has flowers in form, but functionally There are flowers

They are mostly in the accusative, for different reasons.

• στο παρτέρι: παρτέρι is accusative because it follows σε
• μπροστά από το σπίτι: σπίτι is accusative because it follows από
• λουλούδια, βασιλικό, θυμάρι: these are the objects of έχει, so they are also in the accusative

A useful thing to remember is that many neuter nouns look the same in the nominative and accusative:

• το παρτέρι
• το σπίτι
• το θυμάρι

So the case is determined by grammar, even when the form does not visibly change.

Because the sentence is introducing things in a general, indefinite way.

So:

• έχει λουλούδια = there are flowers
• έχει τον βασιλικό would sound more like it has the basil or the specific basil plant

Without articles, the list sounds like a simple mention of what is growing there:

• flowers
• basil
• thyme

This use of bare nouns is very common after existential έχει.

That is a very good question.

The dictionary form for the plant is often ο βασιλικός. But in this sentence, the word comes after έχει, so it appears in the object form.

For a masculine noun like ο βασιλικός, the accusative singular is:

• τον βασιλικό

When the article is omitted, you still keep that noun form:

• βασιλικό

So the sentence uses the form that fits its grammar, not necessarily the dictionary form you first learn.

Because the speaker is listing kinds of plants in a natural, general way.

• λουλούδια = flowers, in a broad plural sense
• βασιλικό = basil, as a plant/herb type
• θυμάρι = thyme, as a plant/herb type

Greek often uses the singular for plant or herb names when talking about them as categories or types, much like English can say There is basil and thyme in the garden.

So this mixture of plural and singular is normal.

Greek word order is fairly flexible.

This sentence starts with the location:

• Στο παρτέρι μπροστά από το σπίτι...

That sets the scene first: in the flowerbed in front of the house...

Then it gives the new information:

• έχει λουλούδια, βασιλικό και θυμάρι

A different order is possible, for example:

• Έχει λουλούδια, βασιλικό και θυμάρι στο παρτέρι μπροστά από το σπίτι.

But the original version sounds very natural because it introduces the place first and then says what is there.

It is simply separating items in a list:

• λουλούδια
• βασιλικό
• θυμάρι

So it works like flowers, basil and thyme in English.

Greek normally does not use a comma before και in a simple list, unless there is a special reason for emphasis or clarity.