Αν σηκώσεις το βαρύ δοχείο μόνη σου, μπορεί να πονέσει η πλάτη σου.

Αν means if and introduces a condition.

So:

Αν σηκώσεις το βαρύ δοχείο μόνη σου...
= If you lift the heavy container by yourself...

This is the normal way to form an if-clause in Greek.

After αν, Greek very often uses the subjunctive form, especially when talking about a possible or future action.

So:

• σηκώνεις = you lift / you are lifting (indicative)
• να σηκώσεις = to lift / that you lift in the subjunctive system
• after αν, the να is not written, but the verb still appears in that subjunctive-type form: αν σηκώσεις

Here σηκώσεις is the aorist subjunctive, which usually presents the action as a single whole event:

If you lift it (once / in that situation)...

This is very natural Greek for a condition like this.

σηκώσεις is second person singular:

• I lift
• you lift → σηκώσεις here

Greek often leaves the subject pronoun out, because the verb ending already tells you who the subject is. So there is an understood you.

It is a noun phrase meaning the heavy container.

The three words agree with each other:

• το = the for a neuter singular noun
• βαρύ = heavy, also neuter singular
• δοχείο = container, neuter singular

So Greek, unlike English, shows agreement on the article and adjective.

βαρύ is the neuter singular form of the adjective βαρύς / βαριά / βαρύ = heavy.

The adjective changes depending on gender:

• masculine: βαρύς
• feminine: βαριά
• neuter: βαρύ

Because δοχείο is neuter, you need βαρύ.

μόνη σου means by yourself or on your own.

Literally it is something like alone yourself, but in natural English we translate it as:

• by yourself
• on your own

This phrase is very common in Greek.

Because μόνη is feminine singular.

The sentence is addressing a woman, so Greek uses the feminine form:

• masculine: μόνος σου = by yourself when speaking to a man
• feminine: μόνη σου = by yourself when speaking to a woman

So this sentence is directed to a female listener.

In μόνη σου, σου helps form the expression meaning yourself / by yourself.

Compare:

• μόνος μου = by myself
• μόνος σου = by yourself
• μόνος του = by himself

With feminine:

• μόνη μου
• μόνη σου
• μόνη της

So σου here is not possession in the usual English sense; it is part of the idiomatic expression.

This σου is the normal possessive form meaning your.

So:

• η πλάτη = the back
• η πλάτη σου = your back

Greek often expresses possession as the X of you, where English would say your X.

Because η πλάτη σου is the subject of πονέσει.

In English we often say:

your back might hurt

Greek works the same way here:

• η πλάτη σου = subject, so it is in the nominative
• την πλάτη σου would be accusative, which would make it an object

So Greek is not saying it may hurt your back here. It is saying your back may hurt.

μπορεί να here means may, might, or can depending on context.

In this sentence, the most natural meaning is:

• may hurt
• might hurt

So:

μπορεί να πονέσει η πλάτη σου
= your back might hurt

This structure is extremely common in Greek:

• μπορεί να βρέξει = it might rain
• μπορεί να αργήσει = he/she may be late

πονέσει is an aorist subjunctive form after μπορεί να.

Very roughly:

• πονάει = it hurts / is hurting (present, ongoing)
• να πονέσει = to hurt / may hurt as a single event or resulting occurrence

In this sentence, Greek is expressing the possible result of lifting the container:

If you lift the heavy container by yourself, your back might start hurting / may get hurt.

So πονέσει fits that idea well.

More or less, yes, but the natural English meaning is usually:

• your back might hurt
• you may hurt your back in some contexts

However, the Greek grammar here is specifically:

your back may hurt

That is why η πλάτη σου is the grammatical subject.

Yes, that is a very natural English interpretation of the overall meaning, even though the Greek structure is literally closer to your back might hurt.

So:

• literal structure: your back might hurt
• natural English meaning in context: you may hurt your back

Both help capture the warning.

Greek word order is more flexible than English.

This sentence is:

Αν σηκώσεις το βαρύ δοχείο μόνη σου, μπορεί να πονέσει η πλάτη σου.

A few things to notice:

• the if-clause comes first
• μόνη σου comes after the object and describes how the action is done
• in the second clause, the verb phrase μπορεί να πονέσει comes before the subject η πλάτη σου

That verb-before-subject order is very common in Greek, especially when introducing what may happen.

Yes. Greek allows some flexibility.

For example, you could also hear:

Αν μόνη σου σηκώσεις το βαρύ δοχείο...

or

Αν σηκώσεις μόνη σου το βαρύ δοχείο...

The original version is perfectly natural. Moving μόνη σου changes emphasis slightly, but not the basic meaning.

It is a real, possible future condition:

If you do this, this may happen.

Greek commonly uses:

• αν + aorist subjunctive for the condition
• then a main clause expressing the likely or possible result

So this is not something unreal like If you had lifted... It is a practical warning about a possible future situation.

Only μόνη σου would change to the masculine form:

Αν σηκώσεις το βαρύ δοχείο μόνος σου, μπορεί να πονέσει η πλάτη σου.

Everything else stays the same.

A rough pronunciation guide:

• Αν = an
• σηκώσεις = see-KO-sees
• το βαρύ δοχείο = to va-REE tho-HEE-o
• μόνη σου = MO-nee soo
• μπορεί να = bo-REE na
• πονέσει = po-NE-see
• η πλάτη σου = ee PLA-tee soo

The written accent mark shows where the stress falls.

A very useful pattern is:

Αν + aorist subjunctive, μπορεί να + aorist subjunctive

In this sentence:

• Αν σηκώσεις... = If you lift...
• μπορεί να πονέσει... = ...it may hurt

This pattern is common for warnings, advice, and possible consequences:

• Αν φας πολύ, μπορεί να αρρωστήσεις.
  If you eat too much, you may get sick.

• Αν τρέξεις έτσι, μπορεί να πέσεις.
  If you run like that, you might fall.