Νυστάζω τώρα, οπότε πάω στο κρεβάτι.

Because Greek often drops the subject pronoun when it is already clear from the verb ending.

• νυστάζω = I feel sleepy
• πάω = I go / I’m going

The ending -ω shows first person singular, so εγώ is not necessary.

You could say Εγώ νυστάζω τώρα..., but that would add emphasis, like I’m sleepy now... rather than someone else.

Νυστάζω means I feel sleepy, I’m drowsy, or I’m getting sleepy.

It does not mean I sleep.
For I sleep / I am sleeping, Greek uses κοιμάμαι.

So:

• νυστάζω = I’m sleepy
• κοιμάμαι = I’m sleeping

Using a verb here is very natural in Greek.

Yes, but they are not exactly the same in feel.

• νυστάζω = I feel sleepy
• είμαι νυσταγμένος / είμαι νυσταγμένη = I am sleepy

Both are possible, but νυστάζω is especially common for the immediate feeling of sleepiness.

Here οπότε means so, therefore, or which is why.

In this sentence:

• Νυστάζω τώρα, οπότε πάω στο κρεβάτι.
• I’m sleepy now, so I’m going to bed.

A useful thing to know is that οπότε can also mean when or whenever in other contexts, but in everyday speech it is very often used as a connector meaning so.

Because οπότε is linking two clauses:

• Νυστάζω τώρα
• οπότε πάω στο κρεβάτι

The comma helps separate the cause/result relationship, much like in English:

• I’m sleepy now, so I’m going to bed.

In normal writing, that comma is natural and expected.

Both πάω and πηγαίνω can mean I go / I’m going.

In everyday Greek, πάω is extremely common and very natural, especially for a specific movement or immediate action like this one.

So these are both possible:

• οπότε πάω στο κρεβάτι
• οπότε πηγαίνω στο κρεβάτι

But πάω sounds especially natural here.

Because the Greek present tense can cover both:

• simple present: I go
• present progressive: I’m going

So πάω can mean either one, depending on context.

Here, because of τώρα and the situation, it clearly means something like:

• I’m going to bed now
• I’m off to bed now

Greek does not need a separate form like English I am going to express that.

Στο is a contraction of:

• σε = to / in / at
• το = the for a neuter singular noun

So:

• σε το κρεβάτι becomes στο κρεβάτι

This contraction is completely normal and standard Greek.

That is just an idiomatic difference between the two languages.

Greek normally says:

• πάω στο κρεβάτι = I’m going to bed

Even though English usually drops the article, Greek keeps it here.

If you say:

• πάω στο κρεβάτι μου

that means I’m going to my bed or to my own bed, which is a bit more specific.

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

The original sentence is natural:

• Νυστάζω τώρα, οπότε πάω στο κρεβάτι.

But you could also say:

• Τώρα νυστάζω, οπότε πάω στο κρεβάτι.

Putting τώρα first gives a little more emphasis to now.

So the meaning stays basically the same, but the emphasis can shift slightly.

A rough pronunciation guide is:

• Νυστάζω τώρα, οπότε πάω στο κρεβάτι.
• nee-STAH-zo TO-ra, O-po-te PA-o sto kre-VA-ti

A few helpful notes:

• Νυστάζω has the stress on στά
• τώρα has the stress on τώ
• οπότε has the stress on πό
• πάω has the stress on πά
• κρεβάτι has the stress on βά

Also, πάω is pronounced in two syllables: PA-o, not as one syllable.