Meghatározzuk a havi díjat.

It has three main parts:

• meg- = a verbal prefix
• határoz = the verb stem
• -zuk / -zzuk = the we ending used here

So meghatározzuk means roughly we determine / we define it.

A useful thing to know is that Hungarian often adds a prefix like meg- to give the verb a more complete, result-oriented meaning. In many contexts, meghatároz is better translated as determine, define, or set than just the simpler base verb.

Also, the spelling has zz because of how the ending attaches to a stem ending in z.

Because Hungarian usually puts the subject inside the verb ending.

In meghatározzuk, the ending tells you the subject is we. So Hungarian does not need a separate pronoun like English does.

You could add mi for emphasis:

Mi meghatározzuk a havi díjat.
= We determine the monthly fee.

But in normal sentences, the pronoun is usually omitted.

This is because Hungarian has definite and indefinite verb conjugation.

Here the object is a havi díjat = the monthly fee, which is definite.
When the direct object is definite, Hungarian normally uses the definite conjugation.

So:

• meghatározzuk = we determine it / the specific thing
• meghatározunk = we determine something non-specific, or with no definite object

Compare:

• Meghatározzuk a havi díjat. = We determine the monthly fee.
• Meghatározunk egy havi díjat. = We determine a monthly fee.

Because díjat is the accusative form, used for the direct object of the verb.

The basic noun is:

• díj = fee

The direct object form is:

• díjat = fee, as the thing being determined

Hungarian usually marks direct objects with -t.
Here an extra vowel appears before -t, giving díj + at = díjat. That extra vowel helps make the word easier to pronounce.

Because in Hungarian, when an adjective directly modifies a noun, usually only the noun gets the case ending.

So:

• havi díj = monthly fee
• havi díjat = monthly fee (as object)

The adjective havi stays unchanged, while díj takes the accusative ending.

This is very normal in Hungarian:

• a nagy ház = the big house
• a nagy házat = the big house (object)

Not nagyat házat, just nagy házat.

havi means monthly or for a month / per month, depending on context.

So havi díj is literally monthly fee.

It is an adjective, describing the noun díj.

A related word you may also see is:

• havonta = monthly, every month

That one is an adverb, not an adjective.

Yes, very often.

Hungarian frequently forms compound nouns, and havidíj is a very natural compound meaning monthly fee.

So these are both understandable:

• a havi díjat
• a havidíjat

Often the one-word compound havidíj feels more like a fixed term, especially in business, contracts, subscriptions, telecom, and billing contexts.

So in real life, Meghatározzuk a havidíjat. would be very common.

a is the Hungarian definite article, meaning the.

So:

• a havi díjat = the monthly fee

Hungarian uses a before consonant sounds and az before vowel sounds:

• a díj
• az összeg

In this sentence, the fee is treated as a specific, identifiable one, so the definite article is used.

If it were non-specific, you might use:

• egy havi díjat = a monthly fee

And then the verb would usually switch to the indefinite conjugation:

• Meghatározunk egy havi díjat.

No, Hungarian word order is more flexible than English word order.

Meghatározzuk a havi díjat is a neutral, straightforward sentence:
We determine the monthly fee.

But the order can change for emphasis or focus. For example:

• A havi díjat meghatározzuk.
  = As for the monthly fee, we determine it.

You may also see the prefix separate in other sentence patterns:

• A havi díjat határozzuk meg.

This happens because Hungarian verbal prefixes often move when something is focused, negated, or questioned.

So the version you were given is the neutral, basic one, but it is not the only possible word order.

It often adds a sense of completion, result, or bringing something to a clear outcome.

So while the base verb is related to determining/deciding/defining, meghatároz often means something like:

• determine
• define
• establish
• set

In this sentence, it suggests arriving at a definite result: the monthly fee gets established.

This is a very common role of Hungarian verbal prefixes: they often change the nuance of the verb, not just its dictionary meaning.

It depends on context.

meghatároz can mean several things in English, including:

• determine
• define
• specify
• set

With a havi díjat, the most natural English translations are often:

• We determine the monthly fee.
• We set the monthly fee.

If this is about pricing, billing, or a contract, set may sound the most natural in everyday English.
If it is more formal or procedural, determine works very well.