Η φίλη μου δυσκολεύεται να κοιμηθεί όταν πίνει καφέ αργά το βράδυ.

In Greek, nouns usually take the definite article much more often than in English. So η φίλη μου literally looks like the friend of me, but it simply means my friend.

A few useful points:

• η = the for a feminine singular noun in the nominative
• φίλη = friend (female)
• μου = my

So Greek normally says:

• η φίλη μου = my friend
• ο φίλος μου = my male friend / my boyfriend depending on context

Dropping the article is possible in some special contexts, but η φίλη μου is the normal neutral phrasing here.

Yes. φίλη is the feminine form, so it refers to a female friend. The masculine form is φίλος.

• ο φίλος μου = my male friend
• η φίλη μου = my female friend

Because Greek nouns have grammatical gender, the article changes too:

• ο with masculine nouns
• η with feminine nouns
• το with neuter nouns

μου is the weak genitive form meaning my (literally of me in structure).

In Greek, possession is often shown like this:

• η φίλη μου = my friend
• το σπίτι μου = my house
• ο αδερφός μου = my brother

So instead of using a separate possessive adjective like English my, Greek very often uses these short pronoun forms after the noun:

• μου = my
• σου = your
• του / της = his / her
• μας = our
• σας = your
• τους = their

Because Greek often leaves out subject pronouns when they are not needed. The verb ending already shows the person and number.

Here:

• δυσκολεύεται = she/he has difficulty
• πίνει = she/he drinks
• κοιμηθεί is understood through the structure after να

Since the subject is already clear from η φίλη μου and from the verb forms, Greek does not need αυτή (she).

Including αυτή would usually add emphasis, like she herself.

Good question. δυσκολεύεται comes from δυσκολεύομαι, which has middle/passive-style endings but an active meaning.

So:

• δυσκολεύομαι = I have difficulty / I struggle
• δυσκολεύεται = she/he has difficulty / struggles

This is common in Greek. Some verbs use these endings without being truly passive in meaning.

Here it does not mean is being made difficult. It simply means:

• she has difficulty
• she finds it hard

After many verbs and expressions, Greek uses να plus a verb form to express something like an infinitive in English.

English says:

• She has difficulty to sleep or more naturally She has difficulty sleeping / falling asleep

Greek does not use an infinitive here. Instead, it uses:

• να κοιμηθεί

So να is introducing the dependent verb, roughly corresponding to English to in structures like to sleep / to fall asleep, although it does not work exactly the same way as English to.

This is about aspect, which is very important in Greek.

• κοιμάται = she is sleeping / she sleeps
• κοιμηθεί (after να) comes from the perfective stem and usually means fall asleep / get to sleep

In this sentence, the idea is not that she has difficulty being in the state of sleep. The idea is that she has difficulty getting to sleep. That is why Greek uses:

• να κοιμηθεί = to fall asleep / to get to sleep

This is a very natural Greek way to express have trouble sleeping, especially when the real issue is actually falling asleep.

Because this sentence describes a repeated or habitual situation:

• whenever she drinks coffee late at night, she has trouble falling asleep

Greek often uses the present tense for this kind of general truth or repeated event.

So:

• όταν πίνει καφέ αργά το βράδυ = when(ever) she drinks coffee late at night

It does not mean only one specific time. It means this happens as a pattern.

In this sentence, it is best understood as when(ever).

Because both verbs describe a habitual situation, όταν has the sense of:

• when
• whenever

So the sentence means something like:

• My friend has trouble falling asleep whenever she drinks coffee late at night.

Greek does not need a separate word for whenever here; the repeated meaning comes from the whole sentence.

Because καφέ here is a general, non-specific object: drink coffee.

Greek often omits the article with objects when speaking in a general or indefinite way, especially with food, drink, and other common activities.

So:

• πίνει καφέ = she drinks coffee
• τρώει ψωμί = she eats bread

If you used the article, it could sound more specific, depending on context:

• πίνει τον καφέ της = she drinks her coffee
• πίνει τον καφέ = she drinks the coffee (a specific coffee)

Greek often uses the accusative as a time expression without a preposition.

So:

• το βράδυ = in the evening / at night
• το πρωί = in the morning
• το μεσημέρι = at noon / in the midday period

And αργά means late.

Together:

• αργά το βράδυ = late at night / late in the evening

This is a very common Greek time expression, and no preposition is needed.

Here το βράδυ is an adverbial expression of time.

Literally:

• το = the
• βράδυ = evening / night

But together, in this kind of expression, it means:

• at night
• in the evening
• during the night/evening period

With αργά, it becomes:

• αργά το βράδυ = late at night

So even though το βράδυ looks like a normal noun phrase, in the sentence it works adverbially.

Yes. Greek word order is more flexible than English, although the given order is very natural.

The sentence:

• Η φίλη μου δυσκολεύεται να κοιμηθεί όταν πίνει καφέ αργά το βράδυ.

is neutral and clear.

You might also hear variations such as:

• Η φίλη μου όταν πίνει καφέ αργά το βράδυ δυσκολεύεται να κοιμηθεί.
• Όταν πίνει καφέ αργά το βράδυ, η φίλη μου δυσκολεύεται να κοιμηθεί.

These mean essentially the same thing, but the focus or rhythm changes a little. Greek allows this kind of movement more freely than English does.

It normally describes a general habit or repeated pattern.

That comes from several clues:

• δυσκολεύεται in the present
• όταν πίνει in the present
• the overall meaning of cause and repeated consequence

So the idea is:

• this is what usually happens to her when she drinks coffee late at night

If you wanted a one-time past event, Greek would use different forms.

Because in Greek the subject of the να clause is often understood from the main clause unless a different subject is clearly introduced.

Here:

• Η φίλη μου δυσκολεύεται = my friend has difficulty
• να κοιμηθεί = to fall asleep

The natural interpretation is that my friend is also the one trying to fall asleep.

If Greek wanted a different subject, it would normally make that clear in the sentence.