Za předpokladu, že pořadatel převezme odpovědnost, můžeme používat ozvučení.

Yes. Za předpokladu, že is a common fixed expression meaning provided that, on the condition that, or assuming that.

Literally:

• za = under / for
• předpokladu = assumption, condition
• že = that

So the whole phrase introduces a condition:

• Za předpokladu, že pořadatel převezme odpovědnost...
• Provided that the organizer takes responsibility...

This is fairly formal or neutral in style. In less formal Czech, people might also use structures like když or pokud, depending on the context.

Because the preposition za here requires the genitive in this fixed phrase: za předpokladu.

So:

• nominative: předpoklad
• genitive: předpokladu

This is something learners often have to memorize as part of the whole expression za předpokladu, že rather than building it from scratch each time.

In Czech, clauses introduced by že are normally separated by a comma.

So:

• Za předpokladu, že pořadatel převezme odpovědnost, ...

The part starting with že is a subordinate clause, and Czech punctuation marks that clearly. Czech uses commas more regularly than English in these situations, so it is good to get used to that pattern.

Pořadatel is in the nominative singular because it is the subject of převezme.

Basic dictionary form:

• pořadatel = organizer

In the clause:

• pořadatel převezme odpovědnost
• the organizer takes/assumes responsibility

Since pořadatel is doing the action, nominative is the expected case.

Převezme is the 3rd person singular form of the verb převzít.

Here it means:

• take over
• assume
• accept

In this sentence, the natural translation is assume responsibility or take responsibility.

A key point: převzít is a perfective verb. Perfective present forms usually have future meaning in Czech. So převezme often corresponds to English will assume / takes on depending on context.

Here the sense is:

• if the organizer assumes responsibility or
• provided that the organizer will take responsibility

Because odpovědnost is the direct object of převezme, so it is in the accusative.

For this noun, the nominative and accusative singular look the same:

• nominative: odpovědnost
• accusative: odpovědnost

So even though the form does not change visibly, its function in the sentence is accusative.

The phrase převzít odpovědnost is very common and means to take/assume responsibility.

This is about aspect.

• používat = imperfective = to use, to be using, to use repeatedly/in general
• použít = perfective = to use once, to apply, to make use of in a single completed instance

So:

• můžeme používat ozvučení suggests we are allowed to use the sound system / use sound equipment in general
• můžeme použít ozvučení would sound more like we can use the sound system once / in this particular instance

In this sentence, používat fits well because the idea is permission for ongoing or general use, not one single completed act.

Ozvučení usually means sound system, sound equipment, or sound reinforcement / amplification setup, depending on context.

It comes from the verb ozvučit = to provide with sound / to amplify / to mic up.

In practical English, here it most likely means:

• the sound system
• audio equipment
• amplification

So můžeme používat ozvučení is something like:

• we can use the sound system
• we can use the audio setup

It is in the accusative singular, because it is the object of používat.

However, ozvučení is a neuter noun whose nominative and accusative singular are identical:

• nominative: ozvučení
• accusative: ozvučení

So, just like with some other Czech nouns, the form does not visibly change even though the grammatical role does.

Yes, it sounds fairly formal or administrative.

Reasons:

• za předpokladu, že is a more formal way to introduce a condition
• převezme odpovědnost is a formal-sounding collocation
• the overall structure sounds like a rule, policy, or official condition

In everyday speech, people might say something simpler, for example:

• Když za to pořadatel vezme odpovědnost, můžeme použít ozvučení.
• Pokud pořadatel převezme odpovědnost, můžeme používat ozvučení.

The original sentence is perfectly natural, but it sounds more like written or official Czech than casual conversation.

The given word order is natural, but Czech word order is fairly flexible.

Original:

• Za předpokladu, že pořadatel převezme odpovědnost, můžeme používat ozvučení.

You could also say:

• Můžeme používat ozvučení, za předpokladu, že pořadatel převezme odpovědnost.

Both are grammatical. The difference is mainly in focus and style:

• starting with Za předpokladu... foregrounds the condition
• starting with Můžeme používat ozvučení... foregrounds the main statement

The version with the condition first feels especially natural in formal instructions or regulations.

Here it most naturally means permission rather than physical ability.

• můžeme používat ozvučení = we may / are allowed to use the sound system

The condition before it makes this especially clear:

• if the organizer assumes responsibility, then permission is granted

Of course, moci can also mean ability in other contexts, but in this sentence the legal/administrative reading of permission is the most likely one.