Αυτό το ξενύχτι δεν μου έκανε καλό· ένιωθα όλη μέρα λες και δεν είχα κοιμηθεί ούτε καν μία ώρα.

ξενύχτι is a noun meaning staying up very late / staying up all night / an all-nighter.

So Αυτό το ξενύχτι means something like:

• this all-nighter
• this staying up late
• this night without sleep

It refers to a specific recent occasion of not sleeping properly.

In Greek, it is very common to use:

• demonstrative + article + noun

So:

• αυτό = this
• το = the (neuter singular article)
• ξενύχτι = neuter singular noun

Together, αυτό το ξενύχτι literally looks like this the all-nighter, but in natural English it is simply this all-nighter.

This pattern is normal Greek:

• αυτό το βιβλίο = this book
• αυτή η μέρα = this day
• αυτό το πρόβλημα = this problem

Greek nouns have grammatical gender, and ξενύχτι happens to be neuter. That is why it takes:

• αυτό rather than αυτή or αυτός
• το rather than η or ο

You generally have to learn a noun’s gender as part of the word.

Literally, it is:

• δεν = not
• μου = to me / for me
• έκανε = did / made
• καλό = good

So the structure is literally it didn’t do me good, which is a very natural Greek way to say:

• it wasn’t good for me
• it didn’t do me any good

Here, μου is an indirect object clitic meaning to me.

Because the subject is Αυτό το ξενύχτι.

So the sentence means:

• This all-nighter didn’t do me any good

Since ξενύχτι is third-person singular, the verb is also third-person singular:

• έκανε = it did / it made

If the subject were I, then you would need έκανα.

ένιωθα is the imperfect of νιώθω / αισθάνομαι and shows an ongoing state in the past.

Here it fits because the speaker is describing how they felt throughout the whole day:

• ένιωθα όλη μέρα = I was feeling all day / I felt all day long

If you said ένιωσα, that would sound more like a single completed feeling or moment:

• I felt at a certain point

So ένιωθα is better for a continuing condition.

όλη μέρα means all day.

In Greek, expressions of duration often appear directly in the accusative, without a preposition. So:

• όλη μέρα = all day
• όλη νύχτα = all night
• τρεις ώρες = for three hours

Literally, όλη μέρα is whole day, but idiomatically it means the whole day / all day long.

λες και means:

• as if
• like
• as though

In this sentence:

• λες και δεν είχα κοιμηθεί...
• as if I hadn’t slept...

It is a very common colloquial expression in Greek. It introduces an imagined comparison, not necessarily something literally true.

You can think of it as similar to:

• It felt like...
• As if...

This is the pluperfect:

• είχα = I had
• κοιμηθεί = past participle form used in perfect tenses

So:

• δεν είχα κοιμηθεί = I had not slept

It is used because the speaker is talking about a past feeling (ένιωθα) and comparing it to an earlier imagined situation:

• I felt all day as if I had not slept...

So the timeline is:

1. the imagined lack of sleep
2. the feeling during the day

That is why the pluperfect works well here.

Greek forms its perfect-type tenses with έχω / είχα + participle.

So from κοιμάμαι (I sleep / I am sleeping), you get:

• έχω κοιμηθεί = I have slept
• είχα κοιμηθεί = I had slept

Even though κοιμάμαι looks like a middle/passive-type verb in form, its meaning here is active in English: sleep.

So κοιμηθεί is just the form required after έχω / είχα in these tenses.

It means:

• not even one hour

Breakdown:

• ούτε = not even / neither
• καν = even
• μία ώρα = one hour

Together, ούτε καν is a strong expression meaning not even.

So:

• δεν είχα κοιμηθεί ούτε καν μία ώρα
• I hadn’t slept even one hour
• more naturally: I hadn’t slept even a single hour

Because ώρα is a feminine noun.

The numeral one agrees in gender:

• masculine: ένας
• feminine: μία / μια
• neuter: ένα

So:

• μία ώρα = one hour

The spelling μία with the accent is often used when the writer wants to make it clearly the numeral one, not just the unstressed article-like form μια.

Yes. It adds emphasis.

Compare:

• δεν είχα κοιμηθεί μία ώρα = I hadn’t slept for an hour
• δεν είχα κοιμηθεί ούτε καν μία ώρα = I hadn’t slept even one hour

The version with ούτε καν sounds stronger and more dramatic. It stresses how little sleep the speaker got.

Greek object pronouns like μου, σου, του, της, μας are usually unstressed clitics and often come before the verb.

So:

• μου έκανε καλό = it did me good

This word order is very normal in Greek. You do not usually place μου after the verb in this kind of sentence.

The mark · is the Greek middle dot.

In modern Greek, it is used somewhat like an English:

• semicolon
• colon

So here it separates two closely related clauses:

• Αυτό το ξενύχτι δεν μου έκανε καλό
• ένιωθα όλη μέρα...

A useful extra note: in Greek, the symbol ; is actually the question mark.

Yes, very often Greek could also use σαν να with a very similar meaning:

• λες και δεν είχα κοιμηθεί...
• σαν να μην είχα κοιμηθεί...

Both can mean as if I hadn’t slept...

However, λες και is especially common in spoken, informal Greek and often has a slightly vivid, expressive feel. The sentence as written sounds very natural.