Δεν μπορώ να σηκώσω το βαρύ κουτί μόνος μου.

In Greek, the subject pronoun is often omitted because the verb ending already shows who the subject is.

• μπορώ = I can
• so εγώ is not necessary

You could say Εγώ δεν μπορώ να σηκώσω το βαρύ κουτί μόνος μου, but that would add emphasis, something like I can’t lift the heavy box by myself.

Δεν is the normal negative particle used before finite verbs in everyday Modern Greek.

So:

• μπορώ = I can
• δεν μπορώ = I cannot / I can’t

It normally goes right before the conjugated verb, so Δεν μπορώ is the standard pattern.

Because the thing being negated here is the main verb μπορώ.

• δεν is used to negate indicative-type verb forms like μπορώ
• μην is used mostly with να clauses, commands, and similar non-indicative structures

So this sentence says:

• Δεν μπορώ... = I can’t...

If you were negating the να clause itself, then μην could appear, for example in a different structure.

Modern Greek does not normally use an infinitive the way English does. After verbs like μπορώ, Greek usually uses:

• να
  • a finite verb form

So:

• μπορώ να σηκώσω = I can lift

This is one of the most important differences from English. You should think of να as introducing the action, where English often uses an infinitive.

This is about aspect.

• σηκώνω = imperfective, focusing on the action as ongoing, repeated, or general
• σηκώσω = perfective, usually focusing on a single complete action

After μπορώ να..., Greek often chooses between these depending on meaning.

Here, να σηκώσω means to manage one complete lift of the box. That is why the perfective form σηκώσω is natural.

Compare:

• Δεν μπορώ να σηκώσω το κουτί = I can’t lift the box up
• Δεν μπορώ να σηκώνω βαριά κουτιά κάθε μέρα = I can’t keep lifting heavy boxes every day

This is the direct object of the verb, meaning the heavy box.

All three words agree grammatically:

• το = neuter singular article
• βαρύ = neuter singular form of heavy
• κουτί = neuter singular noun, box

So Greek is matching the article and adjective to the noun.

Also, for neuter nouns like κουτί, the nominative and accusative singular are often the same in form, so το κουτί can be either subject or object depending on the sentence.

Because κουτί is a neuter noun.

The adjective heavy has different forms:

• βαρύς = masculine
• βαριά = feminine
• βαρύ = neuter

Since κουτί is neuter, Greek uses βαρύ.

So:

• ο βαρύς σάκος = the heavy sack
• η βαριά τσάντα = the heavy bag
• το βαρύ κουτί = the heavy box

μόνος μου means by myself or on my own.

That is different from μόνο, which usually means only or just.

Compare:

• μόνος μου = by myself
• μόνο = only / just

So in this sentence:

• Δεν μπορώ να σηκώσω το βαρύ κουτί μόνος μου
• = I can’t lift the heavy box by myself

Here it means without help, not only.

Yes. μόνος agrees with the person it refers to.

If a man is speaking:

• μόνος μου

If a woman is speaking:

• μόνη μου

Plural forms also change:

• μόνοι μας = by ourselves, for a group of men or mixed group
• μόνες μας = by ourselves, for a group of women

So the sentence as written suggests a male speaker.

In this expression, μου is part of the standard Greek way to say by myself.

Literally, it is something like:

• alone of me

But you should learn it as a fixed pattern:

• μόνος μου = by myself
• μόνος σου = by yourself
• μόνος του = by himself
• μόνη της = by herself
• μόνοι μας = by ourselves

So μου is not redundant in Greek; it is a normal part of the expression.

Yes. Greek word order is more flexible than English, although not completely free.

The neutral order here is:

• Δεν μπορώ να σηκώσω το βαρύ κουτί μόνος μου.

But you could also say:

• Δεν μπορώ μόνος μου να σηκώσω το βαρύ κουτί.
• Το βαρύ κουτί δεν μπορώ να το σηκώσω μόνος μου.

These versions shift the emphasis:

• μόνος μου earlier = stronger emphasis on by myself
• το βαρύ κουτί earlier = stronger emphasis on the heavy box

So the original sentence is natural and neutral, but other orders are possible for focus or style.