Τελευταία ξενυχτάω συχνά, κι έτσι το πρωί χασμουριέμαι συνέχεια.

Here τελευταία means lately / recently.

That is a very common use in Modern Greek. Even though τελευταίος / τελευταία / τελευταίο usually means last, the form τελευταία is also used adverbially to mean in recent times.

So:

• Τελευταία διαβάζω πολύ. = Lately I’ve been studying a lot.
• Τελευταία ξενυχτάω συχνά. = Lately I stay up late often.

It is best to learn τελευταία in this sentence as a fixed time expression meaning lately.

Greek often leaves out subject pronouns when they are not needed.

So instead of saying:

• Εγώ ξενυχτάω
• Εγώ χασμουριέμαι

Greek normally just says:

• ξενυχτάω
• χασμουριέμαι

The verb ending already shows the subject is I:

• -άω in ξενυχτάω = I
• -ιέμαι in χασμουριέμαι = I

You can add εγώ for emphasis, but in a neutral sentence it is usually omitted.

Greek uses the present tense very naturally for current habits, repeated actions, and things that have been happening recently.

So:

• Τελευταία ξενυχτάω συχνά literally looks like Lately I stay up late often
• but in natural English it may be translated as Lately I’ve been staying up late a lot

This is normal. Greek present tense often covers what English expresses with:

• simple present
• present continuous
• present perfect continuous

depending on context.

Yes. This verb can appear in two present-tense forms:

• ξενυχτάω
• ξενυχτώ

Both are used and both mean I stay up late / I spend the night awake.

This is common with many Greek verbs in -άω / -ώ. The longer and shorter forms are both possible, though one may sound more natural depending on the speaker or context.

So you may hear:

• ξενυχτάω συχνά
• ξενυχτώ συχνά

Both are correct.

Ξενυχτάω means to stay up late or to stay awake through the night.

It usually suggests that someone is awake much later than normal, whether because of:

• work
• studying
• going out
• stress
• entertainment

It does not automatically mean insomnia. It is broader than that.

Examples:

• Χτες ξενύχτησα για να τελειώσω τη δουλειά. = Yesterday I stayed up late to finish the work.
• Ξενυχτάει στα πάρτι κάθε Σάββατο. = He/She stays out late at parties every Saturday.

Κι έτσι means and so / so / as a result.

It connects the two parts of the sentence:

• I’ve been staying up late often
• and as a result, I yawn all morning

So the logic is: ξενυχτάω συχνά → κι έτσι → χασμουριέμαι συνέχεια

As for κι, it is just a shorter form of και. In meaning, they are the same here.

• και έτσι
• κι έτσι

Both mean and so / so.

κι is very common in everyday Greek and sounds very natural.

Greek very often uses the definite article with times of day in adverbial expressions.

So:

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

This is simply how Greek commonly expresses these time phrases.

So το πρωί χασμουριέμαι means I yawn in the morning.

Without the article, πρωί can still appear in some expressions, but το πρωί is the standard form here.

Yes, it does look like a passive or middle-passive form, but here it simply means I yawn.

Some Greek verbs have middle/passive endings but active meaning. These are often called deponent verbs in grammar discussions.

So:

• χασμουριέμαι = I yawn
• not I am being yawned

It is just the normal dictionary form of the verb.

This is something English speakers often need to get used to: in Greek, a verb’s form does not always match what English would call active or passive meaning.

They are similar, but not identical.

• συχνά = often / frequently
• συνέχεια = continually / constantly / all the time

So in the sentence:

• ξενυχτάω συχνά = I stay up late often
• χασμουριέμαι συνέχεια = I keep yawning all the time

The first part talks about repeated frequency. The second part sounds stronger and more continuous.

If you switched them, the nuance would change.

Yes. Greek word order is more flexible than English word order.

The given sentence is very natural:

• Τελευταία ξενυχτάω συχνά, κι έτσι το πρωί χασμουριέμαι συνέχεια.

But Greek can move parts around for emphasis. For example:

• Τελευταία συχνά ξενυχτάω...
• Κι έτσι χασμουριέμαι συνέχεια το πρωί.

These are possible, but they may shift the emphasis slightly.

The original version sounds smooth and natural for everyday speech: first the time frame, then the habit, then the consequence.

It sounds natural and conversational, but not slangy.

A few things give it an everyday feel:

• τελευταία for lately
• κι έτσι for so / as a result
• the general rhythm of the sentence

So this is the kind of sentence you could easily say in normal conversation.

It is not overly formal, but it is perfectly correct Greek.