Lassabban mondom Önnek, hogy mindent megértsen.

Lassabban means more slowly.

It is not the location ending -ban/-ben meaning in.

Breakdown:

• lassú = slow
• lassan = slowly
• lassabb = slower
• lassabban = more slowly

So here lassabban is a comparative adverb: slowly → more slowly.

Hungarian often leaves out subject pronouns when they are clear from the verb ending.

So:

• mondom already tells you I say / I am saying it

Because of that, én (I) is unnecessary unless the speaker wants extra emphasis:

• Én mondom Önnek... = I am the one telling you...

This is very normal in Hungarian.

Because Hungarian has two kinds of verb conjugation:

• indefinite conjugation
• definite conjugation

Here:

• mondok = I say / I am saying in a general sense
• mondom = I say it / I am saying it

In this sentence, the thing being said is understood from context, even if it is not explicitly stated. So mondom sounds natural: I’m saying it more slowly to you...

This is very common in Hungarian: the object can be implied, but the verb can still stay in the definite form.

Önnek means to you in a formal/polite way.

Breakdown:

• Ön = formal you
• -nek = dative ending, often meaning to or for

So:

• mondom Önnek = I say it to you

The ending changes by vowel harmony:

• -nak or -nek

Here it is -nek.

Capitalizing Ön is a polite writing convention in Hungarian, similar to showing respect.

So:

• Ön = polite/formal you
• ön = also possible in less formal writing, but the capital letter is respectful

This is especially common in letters, customer service, formal speech, and polite written communication.

Here hogy means so that.

In many sentences, hogy can mean that:

• Azt mondja, hogy... = He says that...

But in this sentence it introduces a purpose clause:

• Lassabban mondom Önnek, hogy mindent megértsen.
• I’m saying it more slowly to you so that you understand everything.

So the idea is purpose or intended result.

Because after hogy in a purpose clause, Hungarian often uses the subjunctive/imperative form of the verb.

So:

• megérti = he/she understands it / you understand it (with formal Ön)
• megértsen = so that he/she may understand it / so that you may understand it

In English, we usually just say:

• so that you understand or
• so that you can understand

Hungarian expresses that idea with this special verb form.

Because Ön is grammatically treated as third person in Hungarian, even though it means you.

That is one of the key things to remember about formal Hungarian.

So:

• informal you = te
• formal you = Ön

And the verb agrees like this:

• te megértsd / megérts type forms for informal address
• Ön megértsen with third-person-style agreement

An informal version of the sentence would be something like:

• Lassabban mondom neked, hogy mindent megérts.

So the meaning is still you, but the grammar behaves like he/she.

Mindent means everything.

Breakdown:

• minden = every / all / everything
• mindent = everything as a direct object

The -t is the accusative ending, which marks the direct object.

So:

• megértsen mindent = understand everything

In this sentence, mindent is the thing that should be understood.

The basic verb is:

• érteni = to understand

With the prefix:

• megérteni = to understand fully / to grasp / to get

The prefix meg- often gives a sense of:

• completion
• success
• reaching a result

So in this sentence, megértsen suggests not just some vague ongoing understanding, but actually coming to understand everything properly.

That is why megérteni is the natural choice here.

Yes, Hungarian word order is quite flexible, and different orders can change the emphasis.

This version:

• Lassabban mondom Önnek, hogy mindent megértsen.

puts lassabban near the front, so it highlights more slowly.

Other orders are possible, for example:

• Önnek mondom lassabban...
• Lassabban mondom, hogy mindent megértsen.

These can sound slightly different in focus, but the basic meaning stays similar.

A good beginner rule is:

• Hungarian word order is not random
• earlier position often gives something more emphasis, contrast, or topic status

Here the sentence naturally foregrounds the manner: more slowly.

Yes, it is formal/polite because it uses Önnek.

A natural informal version would be:

• Lassabban mondom neked, hogy mindent megérts.

Comparison:

• Önnek = to you, formal
• neked = to you, informal

And:

• megértsen matches formal Ön
• megérts matches informal te

So this sentence is the polite version you would use with a stranger, customer, older person, or in a respectful situation.