Δεν θέλω άλλον μπελά.

Because Greek usually drops subject pronouns when the verb already shows who is doing the action.

• θέλω = I want
• So Δεν θέλω already means I don’t want

You could say Εγώ δεν θέλω... if you want extra emphasis on I, but normally it is not needed.

Δεν is the normal word for not before a verb in Greek.

• θέλω = I want
• δεν θέλω = I do not want / I don’t want

It is the standard negation used with indicative verbs in everyday Greek.

Because άλλον has to match μπελά in gender, number, and case.

The noun here is:

• ο μπελάς = the trouble / the hassle / the nuisance

That noun is:

• masculine
• singular

And in this sentence it is the direct object of θέλω, so it goes into the accusative.

So:

• nominative: άλλος μπελάς
• accusative: άλλον μπελά

That is why you see άλλον.

Because μπελά is the accusative singular form of μπελάς.

This is a very common masculine noun pattern in Greek:

• nominative singular: ο μπελάς
• accusative singular: τον μπελά

Since μπελά is the object of θέλω, the accusative is required:

• Δεν θέλω άλλον μπελά.

Yes, it is a normal and very common word, especially in everyday speech.

μπελάς means something like:

• trouble
• hassle
• nuisance
• headache

Depending on context, Δεν θέλω άλλον μπελά can sound like:

• I don’t want any more trouble
• I don’t want another hassle
• I don’t want another headache

It is a very natural colloquial word.

Because Greek often uses a noun without an article when speaking in a general or indefinite way, especially after verbs like want.

So:

• Δεν θέλω άλλον μπελά = I don’t want any more trouble / another hassle

If you said τον μπελά, it would sound like a specific, already known trouble:

• Δεν θέλω τον μπελά = I don’t want that trouble / that particular hassle

Without the article, the phrase sounds more general and idiomatic.

Here it usually means another or any more.

So the sentence suggests:

• there has already been trouble before, or
• the speaker wants to avoid additional trouble

That is why English often translates it more naturally as:

• I don’t want any more trouble

rather than a very literal I don’t want other trouble.

Normally, no, not in standard grammar.

Since μπελάς is masculine singular accusative, the correct form is:

• άλλον μπελά

άλλο is neuter, so it would not agree with μπελά.

So the standard form is:

• Δεν θέλω άλλον μπελά.

The dictionary form is θέλω, which means I want.

This is one of those Greek verbs whose citation form is the 1st person singular present.

Some useful forms:

• θέλω = I want
• θέλεις = you want
• θέλει = he/she/it wants
• θέλουμε / θέλομε = we want
• θέλετε = you (plural) want
• θέλουν / θέλουνε = they want

So in the sentence, θέλω is simply the present tense: I want.

Greek word order is more flexible than English, but not completely free.

The neutral, natural order here is:

• Δεν θέλω άλλον μπελά.

You may also hear variations for emphasis, such as:

• Άλλον μπελά δεν θέλω.

That puts more emphasis on another trouble/hassle.

Still, for a learner, the given order is the safest and most natural one to use.

A rough pronunciation is:

• DEN THE-lo AL-lon be-LA

A few notes:

• δεν sounds like then/den with a soft th/dh sound depending on accent and speech, but learners often approximate it as den
• θέλω has stress on θέ
• άλλον has stress on ά
• μπ at the beginning of μπελά is pronounced like b
• μπελά has stress on the last syllable: -λά

So μπελά sounds like be-LA.

That is a very good observation. Greek often uses μπελάς as a countable noun, where English might prefer an uncountable word like trouble.

So Greek says literally something like:

• I don’t want another hassle/trouble

But natural English often becomes:

• I don’t want any more trouble

This is a normal difference between the two languages, not a sign that the Greek is strange.

Yes, but it means something slightly different.

• Δεν θέλω άλλον μπελά = I don’t want any more / another trouble
• Δεν θέλω κανέναν μπελά = I don’t want any trouble at all

So:

• άλλον focuses on additional trouble
• κανέναν focuses on none at all

Both are correct, but they are not exactly the same.