A barátok között mindig móka van.

A is the definite article in Hungarian, corresponding to English the.

• A barátok = the friends (specific group of friends, in general as a known category)
• Barátok alone would mean simply friends in a more generic or indefinite sense.

In this sentence, A barátok között mindig móka van, the article makes it feel like a general statement about friends as a group / among friends in general, similar to saying in English:

• Among friends there is always fun / Between friends there is always fun.

Hungarian often uses the definite article in these kinds of generalizations about groups (A gyerekek, A kutyák, etc.).

Barát means friend (singular).
Barátok means friends (plural).

Here we’re talking about friends as a group, so the plural is natural:

• A barátok között = among (the) friends.

Formally:

• singular: barát – a friend
• plural: barátok – friends

The plural suffix -ok is used because of vowel harmony (the word has back vowels: a, á, o → it takes -ok, not -ek or -ök).

Között is a postposition meaning between or among.

• A barátok között literally: between/among the friends.

Key points:

• It comes after the noun, not before like an English preposition:
  
  • English: among friends
  • Hungarian: barátok között (friends among/between)
• You can use it with people or things:
  
  • A diákok között – among the students
  • A fák között – among the trees

In this sentence, között is naturally translated as among, because we’re talking about a group, not two specific points.

Both orders are grammatically correct, but they differ slightly in emphasis.

• mindig móka van – neutral way to say there’s always fun; focuses on móka (fun) as the thing that exists.
• mindig van móka – a bit more emphasis on van (the existence of fun, the fact that there is fun).

In everyday speech, mindig móka van sounds very natural and slightly more idiomatic here. It treats móka as the main piece of new information: What is there among friends? Fun.

So:

• A barátok között mindig móka van. – Among friends, there is always fun.
• A barátok között mindig van móka. – Among friends, there is always some fun (subtle emphasis on there being fun).

You’re right that Hungarian often omits van (3rd person singular of to be) in simple predicate sentences:

• Ő tanár. – He/She is a teacher. (no van)
• A ház nagy. – The house is big.

But Hungarian must use van in existential sentences – when you say that something exists / there is / there are:

• Van egy könyv az asztalon. – There is a book on the table.
• Nincs pénz nálam. – I don’t have money on me. (literally: there is no money at me.)

A barátok között mindig móka van is exactly this kind of there is sentence:

• literally: Among the friends always fun is.
• meaning: There is always fun among friends.

So van cannot be dropped here.

Móka is a noun meaning fun, merriment.
Mókás is an adjective meaning funny, amusing.

The sentence uses a noun + van structure to say there is fun:

• móka van – there is fun

If you used mókás, you would need a subject it describes:

• A barátok között mindig mókás a hangulat. – The mood is always funny/cheerful among friends.

So:

• móka van = existential: fun exists / there is fun
• mókás = descriptive: is funny / is amusing (needs something to describe).

In Hungarian, móka behaves like an uncountable / mass noun in this kind of expression, much like fun in English.

English:

• We normally say: There is fun, not There are funs.

Likewise in Hungarian:

• móka van – there is (some) fun.

You could make it plural (mókák vannak), but that sounds strange and concrete, like separate pieces of fun, and is not how people talk about “fun” in general.

For a lot of fun, you’d normally say, for example:

• A barátok között mindig sok móka van. – There is always a lot of fun among friends.

Grammatically, között covers both English meanings:

• between (usually 2 things)
  
  • A két ház között – between the two houses
• among (within a group)
  
  • A barátok között – among (the) friends

English distinguishes strictly between between and among, but Hungarian között does not; context tells you which English word to choose.

In this sentence, since we talk about a group of friends, among is the most natural translation.

Yes, you can say:

• Barátok között mindig móka van.

It’s still correct and natural. The difference is very small:

• A barátok között… – slightly more like Among the friends / Among friends (as a known group).
• Barátok között… – more like Among friends… in a very general, proverb-like way.

Native speakers use both; in this kind of generic, “wisdom about life” type sentence, dropping A often feels a bit more proverbial.

Approximate pronunciation (stress is always on the first syllable of each word):

• A – [ɒ] like a short open “o”
• barátok – [bɒ-RAA-tok]
  
  • ba – [bɒ]
  • rát – [raːt] (long á, like “a” in “father” but longer)
  • ok – [ok]
• között – [KÖ-zött]
  
  • kö – [kø] (like German ö, similar to the vowel in British “bird” but fronted)
  • zött – [zøtː] (short ö, double t is lengthened)
• mindig – [MIN-dig] (both i like “ee” in “see”, but short)
• móka – [MOː-kɒ] (long ó, like a longer “o”)
• van – [vɒn]

Put together, slowly:
[ɒ bɒ-RAː-tok KØ-zøtː MIN-dig MOː-kɒ vɒn].

Yes, several variants keep roughly the same meaning:

• Barátok között mindig jó a hangulat.

  • Among friends, the mood is always good.

• Barátok között mindig vidám az élet.

  • Among friends, life is always cheerful.

• Barátok között sosem unalmas.

  • Among friends, it’s never boring.

But A/Barátok között mindig móka van is short, idiomatic, and very close to the English idea There’s always fun among friends.