Θέλω ένα τοστ με τυρί και ντομάτα.

Because Greek often leaves out subject pronouns when they are not needed. The verb form already tells you who the subject is.

• Θέλω = I want
• so Greek does not need εγώ here

You could say Εγώ θέλω ένα τοστ..., but that adds emphasis, like I want a toastie... or As for me, I want.... The plain, natural version is just Θέλω.

Θέλω means I want.

Yes, it is natural and very common in everyday Greek, especially in casual situations like cafés, snack bars, or bakeries. That said, it can sound a bit direct depending on tone and context, just like I want in English.

A more polite version would be:

• Θα ήθελα ένα τοστ με τυρί και ντομάτα. = I would like a toastie with cheese and tomato.
• You can also add παρακαλώ = please

So:

• casual and common: Θέλω ένα τοστ...
• more polite: Θα ήθελα ένα τοστ...

Because ένα is the indefinite article meaning a / an, and τοστ is a neuter singular noun.

Greek indefinite articles change for gender:

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

Since τοστ is neuter, you say:

• ένα τοστ = a toastie / a toasted sandwich

This also shows that τοστ is treated as a countable item here, not as general toast in the English uncountable sense.

In everyday Greek, τοστ usually means a toasted sandwich or toastie, not just a slice of toasted bread.

So ένα τοστ με τυρί και ντομάτα means something like:

• a toastie with cheese and tomato
• a toasted sandwich with cheese and tomato

It is a loanword, and it is very common in spoken Greek.

Because in this sentence they are being used as ingredients/fillings in a general sense:

• με τυρί και ντομάτα = with cheese and tomato

This is very natural in Greek. English does the same thing in phrases like with cheese and tomato.

If you added articles, it would sound more specific, like talking about particular cheese or a particular tomato:

• με το τυρί και τη ντομάτα = with the cheese and the tomato

That is usually not what you want when ordering food. The version without articles is the normal one here.

Yes. με normally takes the accusative in Modern Greek.

In this sentence:

• με τυρί
• και ντομάτα

the nouns appear after με, so they are functioning in the accusative. But you do not see much change here because:

• τυρί has the same form in nominative and accusative
• ντομάτα also stays ντομάτα when used without an article

If you included the article, the accusative becomes clearer:

• με το τυρί
• με τη ντομάτα

Because in Modern Greek, the combination ντ is commonly used to represent the d sound.

So:

• ντομάτα is pronounced roughly do-MA-ta

This is normal Greek spelling. A few other useful patterns are:

• μπ often gives a b sound
• γκ or γγ often gives a g sound

So the spelling may look surprising at first, but it follows common Greek sound patterns.

Greek word order is more flexible than English, but the given sentence is the most neutral and natural order:

• Θέλω ένα τοστ με τυρί και ντομάτα.

You can move things around for emphasis, for example:

• Ένα τοστ με τυρί και ντομάτα θέλω.

This still means the same thing, but it puts more focus on what you want.

In real-life ordering, people also often shorten it to:

• Ένα τοστ με τυρί και ντομάτα, παρακαλώ.

That is very natural in a café or snack bar.

A rough pronunciation is:

THE-lo EH-na tost me ti-REE ke do-MA-ta

A few notes:

• Θ sounds like th in think
• έ shows the stress in Θέλω
• τυρί is stressed on the last syllable: ti-REE
• ντομάτα is stressed in the middle: do-MA-ta
• και is usually pronounced roughly like ke

So the stress pattern is:

• Θέλω
• ένα
• τοστ
• με
• τυρί
• και
• ντομάτα

The most common polite version is:

• Θα ήθελα ένα τοστ με τυρί και ντομάτα.

This literally means I would like a toastie with cheese and tomato.

If you want to sound even more natural and polite, add παρακαλώ:

• Θα ήθελα ένα τοστ με τυρί και ντομάτα, παρακαλώ.

That is a very useful pattern for ordering many things in Greek.