Learn Hardcore Greek: Στο σπίτι προσπαθούμε να πετάμε λιγότερα σκουπίδια κάθε μέρα. - At home we try to throw away less garbage every day.

So στο σπίτι = “in/at the house.”
In this sentence it is best translated as “At home”, because Greek often uses στο σπίτι where English would say “at home.”

Why does Greek say στο σπίτι when English just says “at home” without “the”?

English uses “home” almost like an adverb: at home, go home, stay home (no article).

Greek normally treats σπίτι as a regular noun and uses the article:

στο σπίτι = at the house / at home
από το σπίτι = from (the) house
για το σπίτι = for the house

So in idiomatic Greek, στο σπίτι is the normal way to say “at home,” even though a literal translation would be “at the house.” The article το is required here because σπίτι is used as a regular noun in a prepositional phrase.

Why is the possessive “our” not used? Why not στο σπίτι μας?

You can say στο σπίτι μας, and it is correct: “at our house / at our home.”

However, in many everyday contexts, when people say στο σπίτι, it is already understood they mean their own home, not some random house. Greek often omits possessive pronouns when the owner is obvious:

Πάω στο σπίτι. = I’m going home. (my home is understood)
Είμαι στο δωμάτιο. = I’m in (my) room.

So the shorter στο σπίτι here is natural and does not feel incomplete. If you really want to stress “our home (not someone else’s),” you’d use στο σπίτι μας.

What is the function of να in προσπαθούμε να πετάμε? Is it like English “to”?

In προσπαθούμε να πετάμε, the να introduces a subjunctive clause. It’s not exactly the infinitive “to,” but in many sentences it fills a similar slot:

προσπαθώ να … = I try to …
θέλω να … = I want to …
μπορώ να … = I can …

Greek doesn’t really use an infinitive form the way English does. Instead, it uses να + a finite verb (in the subjunctive mood). So:

προσπαθούμε να πετάμε ≈ “we try to throw away”

Grammar-wise:

προσπαθούμε = we try (present indicative)
να πετάμε = that we throw (present subjunctive, ongoing / repeated action)

Together: “At home we try to throw away less rubbish every day.”

What is the difference between να πετάμε and να πετάξουμε here?

Both are subjunctive forms of πετάω (“throw away / throw / fly”), but they differ in aspect:

να πετάμε – imperfective aspect (ongoing, repeated, habitual)
- suggests a continuing or repeated action
- here: “to be throwing away (as a habit)”
να πετάξουμε – aorist aspect (single, whole, one-off or total event)
- focuses on the result or one complete event
- would feel more like: “to throw away (on one occasion / in total)”

In this sentence:

προσπαθούμε να πετάμε λιγότερα σκουπίδια κάθε μέρα
= we try, as a regular habit, to throw away less rubbish every day.

If you said:

Σήμερα προσπαθούμε να πετάξουμε λιγότερα σκουπίδια.
= Today we’re trying to throw away less rubbish (on this one occasion).

So να πετάμε fits better with κάθε μέρα (“every day”) because it refers to a regular, ongoing pattern.

Does πετάμε here mean “we fly” or “we throw away”? How do we tell?

The verb πετάω / πετώ has two main meanings:

to fly
to throw / to throw away

In this sentence:

πετάμε σκουπίδια = we throw away rubbish

We know the meaning is “throw away” because of the object:

σκουπίδια = garbage, rubbish, trash
→ you can’t meaningfully “fly rubbish,” but you can throw away rubbish.

Context usually makes the meaning clear. Some examples:

Το αεροπλάνο πετάει. = The airplane is flying.
Πετάμε τα σκουπίδια. = We throw the rubbish away.
Μην πετάς πράγματα από το παράθυρο. = Don’t throw things out of the window.

Why is it λιγότερα σκουπίδια and not λιγότερο σκουπίδια?

Λιγότερα is the neuter plural form of “less / fewer”, and it agrees in gender and number with σκουπίδια:

σκουπίδια = rubbish, trash (neuter plural noun)
λιγότερα = less / fewer (neuter plural comparative of λίγος)

In Greek, adjectives must agree with the noun:

λίγα σκουπίδια = a few / little rubbish
λιγότερα σκουπίδια = less / fewer rubbish

So:

λιγότερα (plural) matches σκουπίδια (plural).
λιγότερο σκουπίδια would be ungrammatical because λιγότερο is singular, but σκουπίδια is plural.

Also, although English distinguishes “less” vs “fewer,” Greek generally just uses λιγότερα here; it covers both ideas.

What exactly does κάθε μέρα mean, and is there a difference from κάθε ημέρα?

κάθε μέρα = “every day”.

κάθε = every / each
μέρα = day (informal / everyday word)

κάθε ημέρα means the same thing, but ημέρα is the more formal or “full” form of μέρα:

μέρα – informal, very common in speech
ημέρα – more formal, often in writing, announcements, official language

So in everyday speech and writing, κάθε μέρα is much more natural.

You could also say:

Κάθε μέρα πετάμε λιγότερα σκουπίδια. = Every day we throw away less rubbish.
Προσπαθούμε καθημερινά να πετάμε λιγότερα σκουπίδια.
(καθημερινά = daily, every day)

Can the word order be changed? For example: Προσπαθούμε στο σπίτι να πετάμε λιγότερα σκουπίδια κάθε μέρα?

Yes, Greek word order is fairly flexible, and your version is grammatical:

Στο σπίτι προσπαθούμε να πετάμε λιγότερα σκουπίδια κάθε μέρα.
Προσπαθούμε στο σπίτι να πετάμε λιγότερα σκουπίδια κάθε μέρα.

Both are correct. The differences are slight and mostly about emphasis:

Starting with Στο σπίτι puts a little extra emphasis on “At home (as opposed to elsewhere)”.
Starting with Προσπαθούμε puts the focus first on “We try”.

In normal conversation, both word orders would sound natural, but beginning with Στο σπίτι feels like setting the scene: “At home, we try…”

Sometimes people say Είμαι σπίτι without στο. Why is it στο σπίτι here but σπίτι alone in other phrases?

Greek can use σπίτι in two main ways:

With a preposition and article – as a regular noun:
- στο σπίτι = at (the) house / at home
- από το σπίτι = from (the) house
- για το σπίτι = for the house
Without article or preposition – as an adverb-like word:
- Είμαι σπίτι. = I’m at home.
- Πάω σπίτι. = I’m going home.
- Μένω σπίτι. = I stay at home.

In your sentence, we have a clear prepositional phrase στο σπίτι starting the sentence (“At home, we try…”), so the στο is used.

If you rewrote the sentence more adverbially, you could say:

Σπίτι προσπαθούμε να πετάμε λιγότερα σκουπίδια κάθε μέρα.

This is grammatically possible but sounds less natural here. The version with στο σπίτι is the standard and idiomatic one for “At home, we try…”.