Μην πετάς τα σκουπίδια στον δρόμο.

Because Μην is the normal way to make a negative command in Modern Greek.

• Δεν is used for simple negation in statements:
  • Δεν πετάς τα σκουπίδια στον δρόμο. = You don’t throw trash in the street.
• Μην is used when telling someone not to do something:
  • Μην πετάς τα σκουπίδια στον δρόμο. = Don’t throw trash in the street.

So if you want to say don’t ..., you usually need μη(ν), not δεν.

Formally, πετάς looks exactly like the 2nd person singular present form of πετάω / πετώ.

But after Μην, Greek uses this form to express a negative command. So in this sentence, πετάς is not just a plain statement form in meaning; it functions like:

• Don’t throw ...
• Don’t be throwing ...

This is very common in Modern Greek. Greek does not use the regular imperative form after Μην. Instead, it uses μη(ν) + subjunctive-looking form, which often looks the same as the present form.

Modern Greek normally does not use a separate negative imperative form for you commands. Instead, it uses:

• Μην + verb

Compare:

• Positive command: Πέτα τα σκουπίδια στον δρόμο. = Throw the trash in the street.
• Negative command: Μην πετάς τα σκουπίδια στον δρόμο. = Don’t throw the trash in the street.

So this is just how Greek forms negative commands.

τα is the definite article here, meaning the.

• τα σκουπίδια = the trash / the garbage

A few helpful points:

• σκουπίδια is a neuter plural noun.
• The nominative/accusative plural article for neuter nouns is τα.
• In this sentence, the noun is the direct object, so the accusative is used.
• For neuter plural nouns, nominative and accusative look the same:
  • τα σκουπίδια

So τα is simply the correct article for σκουπίδια in this form.

Greek often uses the plural σκουπίδια to mean trash, garbage, litter in a general sense.

So:

• σκουπίδι = a piece of trash / a trash item
• σκουπίδια = trash / garbage / litter

This is similar to how English often uses a mass or collective idea: trash, garbage, litter.

In everyday Greek, τα σκουπίδια is extremely natural.

Because στον is the contracted form of:

• σε + τον = στον

So:

• στον δρόμο literally comes from σε τον δρόμο
• meaning in/on the street depending on context

This contraction is normal and standard in Modern Greek.

Other common contractions:

• σε + το = στο
• σε + τη(ν) = στην
• σε + τους = στους

Because after στον, the noun must be in the accusative case.

The dictionary form is:

• ο δρόμος = the street / road

But after σε / στον / στην / στο, Greek normally uses the accusative:

• στον δρόμο = in/on the street

So:

• nominative: ο δρόμος
• accusative: τον δρόμο

And since στον = σε + τον, you get:

• στον δρόμο

It usually means in/on the street here, depending on how English would naturally express it.

Greek σε + accusative covers several meanings that English splits up differently:

• in
• on
• at
• sometimes to / into

In this sentence, στον δρόμο means something like:

• on the street
• in the street
• idiomatically, in the roadway / out on the street

In natural English, the best translation is usually on the street or in the street, depending on the context.

Here it means to throw or to toss.

So:

• πετάω τα σκουπίδια = throw away the trash / throw trash

But this verb can also have other meanings in other contexts, such as:

• to fly (for birds, planes, etc.)
  • Το πουλί πετάει. = The bird is flying.

So the exact meaning depends on the object and context. With τα σκουπίδια, it clearly means throw.

Because πετάς is 2nd person singular informal:

• Μην πετάς ... = said to one person, informally

If you were speaking to:

• more than one person, or
• one person formally,

you would use:

• Μην πετάτε τα σκουπίδια στον δρόμο.

So the choice depends on who is being addressed.

Yes, and that is a very useful question because it involves aspect.

Greek often contrasts:

• Μην πετάς = imperfective
• Μην πετάξεις = perfective

Very roughly:

• Μην πετάς often sounds more like a general prohibition or repeated action:
  • Don’t throw trash in the street
  • Don’t be throwing trash in the street
• Μην πετάξεις often refers more to a single completed act:
  • Don’t throw the trash in the street / Make sure you don’t throw it there

In many situations, both are possible, but they are not exactly identical in nuance.

Yes, it is natural, especially if speaking directly to one person.

However, for a public sign or general instruction, Greek often prefers:

• Μην πετάτε σκουπίδια στον δρόμο.
• Μην πετάτε τα σκουπίδια στον δρόμο.

Using πετάτε makes it sound like a general public instruction addressed to everyone politely/plurally.

Also, in signs, Greek often drops the article:

• Μην πετάτε σκουπίδια στον δρόμο.

That sounds very natural too.

Yes, Greek word order is more flexible than English.

The neutral order here is:

• Μην πετάς τα σκουπίδια στον δρόμο.

But you could move things around for emphasis, for example:

• Μην πετάς στον δρόμο τα σκουπίδια.
• Τα σκουπίδια μην τα πετάς στον δρόμο.

These versions shift emphasis or sound more marked. The original sentence is the most straightforward and neutral one for a learner.

A simple pronunciation guide would be:

• Μην ≈ meen
• πετάς ≈ pe-TAS
• τα ≈ ta
• σκουπίδια ≈ skoo-PEE-thya
• στον ≈ ston
• δρόμο ≈ DRO-mo

So roughly:

meen pe-TAS ta skoo-PEE-thya ston DRO-mo

A few notes:

• η / ι / υ / ει / οι are all pronounced like ee.
• δ in Modern Greek sounds like the th in this, not like English d.
• Stress matters:
  • πετάς
  • σκουπίδια
  • δρόμο

δρόμος can mean both road and street, depending on context.

In this sentence, English will usually prefer:

• street

because the idea is about throwing trash in a public street area.

But the Greek noun itself is broader than just one English word.

Yes. That is also grammatical and natural.

Compare:

• Μην πετάς τα σκουπίδια στον δρόμο.
• Μην πετάς σκουπίδια στον δρόμο.

The version with τα sounds more like the trash or a more specific object/set of trash. The version without τα sounds a bit more general, like Don’t throw trash / litter in the street.

In public notices, dropping the article is often very natural.