Kötényben díszítjük a bögrét.

Yes, the suffix -ban/-ben basically means in or inside, so kötényben is literally in an apron.

But with clothing, Hungarian often uses this structure to mean wearing that item. So here kötényben is naturally understood as wearing an apron, not that something is physically inside the apron.

This is similar to how Hungarian can say someone is kabátban (in a coat) or cipőben (in shoes) to mean they are dressed that way.

This is because of vowel harmony.

Hungarian chooses between -ban and -ben depending on the vowels in the word:

• back-vowel words usually take -ban
• front-vowel words usually take -ben

kötény has front vowels (ö, é), so it takes -ben:

• kötény → kötényben

Because bögrét is the accusative form, which marks the direct object of the verb.

Here, the thing being decorated is the mug, so Hungarian marks it with the accusative:

• bögre = mug
• bögrét = mug + accusative marker

In this word, the final -e lengthens to -é before the accusative -t:

• bögre → bögrét

This is a common pattern with many nouns ending in -a/-e.

Because Hungarian uses definite conjugation when the verb has a definite object.

Here the object is a bögrét = the mug, which is definite, so the verb must also be in the definite form:

• díszítjük = we decorate it / the definite thing
• díszítünk = we decorate something indefinite, or just we are decorating

So:

• Díszítjük a bögrét. = We decorate the mug.
• Díszítünk egy bögrét. = We decorate a mug.

This is one of the most important grammar points in Hungarian.

It is built into the verb díszítjük.

Hungarian verbs usually show the subject, so a separate pronoun is often unnecessary. In díszítjük, the ending tells you that the subject is we.

So Hungarian does not need mi here.

• Díszítjük a bögrét. = We decorate the mug.
• Mi díszítjük a bögrét. = We decorate the mug.
  This version adds emphasis, as if contrasting we with someone else.

a is the Hungarian definite article, meaning the.

Hungarian has two forms of the definite article:

• a before consonants
• az before vowels

So:

• a bögre = the mug
• az alma = the apple

Since bögre begins with b, the article is a.

Hungarian word order is much more flexible than English word order, and it often depends on what is being highlighted.

Putting Kötényben first gives the sentence a kind of setting or frame:

• Kötényben díszítjük a bögrét.
  = As for clothing / in terms of the situation, we decorate the mug wearing an apron.

It can sound like the speaker is foregrounding the circumstance wearing an apron.

In Hungarian, different word orders are often possible, but the emphasis changes. So the first position is frequently important for information structure, not just grammar.

Grammatically, kötényben literally has the form in the apron, so in theory it could describe location.

But in a sentence like this, the natural reading is that the people doing the decorating are wearing an apron.

Context is what decides this. With clothing words, Hungarian very often uses -ban/-ben to describe what someone is wearing, so that is the normal interpretation here.

Not with the same meaning.

• kötényben = wearing an apron
• köténnyel = with an apron

The suffix -val/-vel usually means with, often in the sense of using something or being accompanied by it. So köténnyel díszítjük a bögrét would sound more like the apron is somehow being used in the decorating process, which is probably not what is meant.

So kötényben is the correct form if the idea is that the person is dressed in an apron.

The dictionary form is díszíteni, meaning to decorate.

Some useful related forms are:

• díszít = he/she/it decorates
• díszítek = I decorate
• díszítünk = we decorate something indefinite
• díszítjük = we decorate it / the definite thing

So in this sentence, díszítjük is the 1st person plural definite form of díszíteni.