Δεν μπορώ να κοιμηθώ, γιατί βήχω όλο το βράδυ.

Because Modern Greek does not use an infinitive the way English does. After verbs like μπορώ (I can), Greek normally uses να + a verb form called the subjunctive.

So:

• μπορώ να κοιμηθώ = I can fall asleep / I can get to sleep
• literally, something like I can that I fall asleep

That sounds strange in English, but it is completely normal in Greek.

This is an aspect question.

• κοιμάμαι = I sleep / I am sleeping
• κοιμηθώ = I fall asleep / I get to sleep

In this sentence, the idea is not really I cannot be in a sleeping state, but rather I cannot manage to fall asleep. That is why Greek uses κοιμηθώ, the aorist subjunctive form.

So:

• Δεν μπορώ να κοιμηθώ = I can’t get to sleep
• Δεν μπορώ να κοιμάμαι would sound odd in most contexts, unless you meant something more like I’m not able to be sleeping or I can’t sleep as a general state, which is less natural here.

δεν is the normal negation used before finite verbs in statements.

• μπορώ = I can
• δεν μπορώ = I can’t

So Δεν μπορώ να κοιμηθώ simply means I can’t fall asleep / I can’t sleep.

A learner may wonder why Greek does not use μη(ν) here. That is because μη(ν) is mainly used with the subjunctive, imperative, and certain non-indicative structures. Here the main verb is μπορώ, so the correct negation is δεν.

βήχω means I cough or I am coughing.

In this sentence it has an ongoing or repeated sense:

• βήχω όλο το βράδυ = I cough all night / I’ve been coughing all night

The present tense works well because the coughing is happening repeatedly over a period of time.

Because the sentence describes an ongoing repeated action over the whole night.

• βήχω = I am coughing / I keep coughing
• this matches όλο το βράδυ = all night

If you used an aorist-type form, it would suggest a single completed event rather than repeated coughing throughout the night, so it would not fit as well.

Literally it means the whole night/evening, but in natural English here it is best understood as all night.

Breakdown:

• όλο = whole / all
• το βράδυ = the night / the evening depending on context

Together:

• όλο το βράδυ = all night / the whole night

This is a very common Greek way to express duration.

Because βράδυ is a neuter noun, so the adjective must agree with it.

• masculine: όλος
• feminine: όλη
• neuter: όλο

Since βράδυ is neuter, Greek uses:

• όλο το βράδυ

This agreement is one of the basic patterns learners need to get used to in Greek.

Yes. It is in the accusative, which is often used in Greek for expressions of time and duration.

So in βήχω όλο το βράδυ, the phrase όλο το βράδυ functions adverbially, meaning for the whole night / all night.

This is very common in Greek:

• όλη μέρα = all day
• όλη νύχτα = all night
• όλο το πρωί = all morning

Yes, βράδυ often means evening, but in expressions like όλο το βράδυ it can cover the nighttime period more broadly, and the natural English translation is often all night.

Greek can also use:

• όλη νύχτα = all night

So both ideas exist, but όλο το βράδυ is a perfectly natural expression.

Yes. γιατί can mean both:

• why?
• because

The meaning depends on context and intonation.

Examples:

• Γιατί βήχεις; = Why are you coughing?
• Δεν μπορώ να κοιμηθώ, γιατί βήχω όλο το βράδυ. = I can’t sleep, because I cough all night.

This is very common in Greek and usually does not cause confusion for native speakers.

Yes, you could say:

• Δεν μπορώ να κοιμηθώ, επειδή βήχω όλο το βράδυ.

That would also mean I can’t sleep because I cough all night.

In many everyday situations, γιατί is more common and conversational. επειδή can sound a little more explicit or slightly more formal, though both are normal Greek.

The comma separates the main clause from the clause giving the reason.

• Δεν μπορώ να κοιμηθώ = main clause
• γιατί βήχω όλο το βράδυ = reason clause

In Greek writing, a comma before γιατί in this kind of sentence is standard and natural.

No, Greek word order is more flexible than English word order, although this version is very natural and neutral.

The given sentence:

• Δεν μπορώ να κοιμηθώ, γιατί βήχω όλο το βράδυ.

You could also hear variations like:

• Δεν μπορώ να κοιμηθώ γιατί όλο το βράδυ βήχω.
• Όλο το βράδυ βήχω, γι’ αυτό δεν μπορώ να κοιμηθώ.

The basic meaning stays similar, but the emphasis changes a little. The original sentence is a straightforward, natural way to say it.

A rough pronunciation is:

• κοιμηθώ ≈ kee-mee-THO

More precisely:

• κοι- sounds like kee
• -μη- sounds like mee
• -θώ has θ like th in think, and the stress falls on this last syllable

So the stress is important:

• κοιμηθώ

Likewise:

• βήχω is roughly VEE-ho or VEE-kho, with the stress on the first syllable

In Greek, Δεν μπορώ να κοιμηθώ most directly means I can’t fall asleep / I can’t get to sleep.

But in natural English, I can’t sleep is often the best translation, because that is how English usually expresses the same idea in everyday speech.

So:

• grammatically close: I can’t fall asleep
• naturally in English: I can’t sleep

Both are good, depending on how literal you want to be.