Το άλλο σκαμπό είναι πιο άνετο, αλλά πάνω στον δίσκο δεν χωράει και η κανάτα μαζί με τις κούπες.

Because they all agree with σκαμπό, which is a neuter noun in Greek.

• το σκαμπό = the stool
• το άλλο σκαμπό = the other stool
• είναι πιο άνετο = is more comfortable

Greek articles and adjectives must match the noun in gender, number, and case. Also, σκαμπό is a loanword and is often treated as indeclinable, so the noun itself stays σκαμπό, while the article and adjective show the grammar.

Here it most naturally means the other stool.

That is because of the definite article το:

• το άλλο σκαμπό = the other stool
• άλλο σκαμπό = another / a different stool

So the article makes a big difference.

Greek commonly forms the comparative with πιο + adjective.

So:

• άνετο = comfortable
• πιο άνετο = more comfortable

This is the most common everyday way to make comparatives. Greek also has a one-word comparative:

• ανετότερο

So both are possible:

• πιο άνετο
• ανετότερο

But πιο άνετο sounds very natural and common in modern spoken Greek.

It means on the tray or on top of the tray.

The structure is:

• πάνω σε = on / on top of
• σε τον becomes στον

So:

• πάνω σε τον δίσκο → πάνω στον δίσκο

Also:

• δίσκος is masculine
• accusative singular: τον δίσκο

So πάνω στον δίσκο is a very normal way to say on the tray.

Because after σε and expressions like πάνω σε, Greek normally uses the accusative.

The noun is:

• nominative: ο δίσκος
• accusative: τον δίσκο

And σε τον contracts to στον:

• σε τον δίσκο → στον δίσκο

So:

• πάνω στον δίσκο = on the tray

Here χωράει means fits, has room, or can be accommodated in the available space.

The verb is χωράω / χωρώ and it is used when something physically fits somewhere.

Examples:

• Δεν χωράει στο κουτί. = It doesn’t fit in the box.
• Χωράνε όλοι στο αυτοκίνητο; = Do they all fit in the car?

In your sentence, the idea is that there is not enough room on the tray.

Also, you may see both:

• χωράει
• χωρά

Both are used in Modern Greek.

Because the grammatical subject is really η κανάτα alone, and μαζί με τις κούπες is an added phrase meaning together with the cups.

So the structure is basically:

• η κανάτα = the jug
• μαζί με τις κούπες = together with the cups

That is why the verb can stay singular:

• δεν χωράει η κανάτα μαζί με τις κούπες

If Greek treated both nouns as a full coordinated subject, you would expect plural:

• η κανάτα και οι κούπες δεν χωράνε

So μαζί με does not work exactly the same way as και.

Here και is better understood as also, too, or even rather than a simple and.

So the meaning is something like:

• the jug too, together with the cups, doesn’t fit
• there isn’t room for the jug as well as the cups

This is a very common use of και in Greek. It often adds the sense of also / as well depending on context.

μαζί με means together with or along with.

It shows that the cups are accompanying the jug:

• η κανάτα μαζί με τις κούπες = the jug together with the cups

This is slightly different from using plain και:

• η κανάτα και οι κούπες = the jug and the cups

With μαζί με, the first noun is more central, and the second noun is presented as accompanying it.

Because με takes the accusative in Modern Greek.

The noun is:

• nominative plural: οι κούπες
• accusative plural: τις κούπες

Since the phrase is μαζί με, you need the accusative:

• μαζί με τις κούπες

So:

• οι κούπες = the cups, as subject
• τις κούπες = the cups, after με

Because Greek word order is fairly flexible.

In this sentence, Greek first highlights:

1. the location: πάνω στον δίσκο
2. the lack of space: δεν χωράει
3. what doesn’t fit: και η κανάτα μαζί με τις κούπες

This kind of order sounds natural in Greek. English usually prefers to name the subject earlier, but Greek often moves it later for focus or flow.

So the sentence structure is not unusual; it is just a more natural Greek way of organizing the information.