Na této straně je zvuk lepší.

A very literal breakdown is:

• Na = on / at
• této = this
• straně = side
• je = is
• zvuk = sound
• lepší = better

So the sentence is literally:

On this side, the sound is better.

Depending on context, strana can mean side, but also sometimes page or party. Here it most naturally means side.

Because after the preposition na, Czech usually changes the form of the following words according to case.

Here, na této straně is describing a location:
on this side / on this page / at this side

So Czech uses the locative case after na when it means location.

That is why:

• tato strana = this side (basic dictionary form, nominative)
• na této straně = on this side (locative after na)

Both této and straně are changed to match the locative.

Yes, na can take different cases depending on meaning.

A very useful rule is:

• na + locative = location
  
  • na této straně = on this side
• na + accusative = direction / movement toward something
  
  • na tuto stranu = to this side

So in your sentence, nothing is moving. It describes where something is true, so Czech uses locative:

• Na této straně je zvuk lepší. = On this side, the sound is better.

If you were talking about movement, you might say:

• Jdi na tuto stranu. = Go to this side.

Tato is the nominative feminine singular form of this.

But here the noun strana is after na in a location meaning, so it must be in the locative singular. The demonstrative has to agree with the noun, so it changes too:

• tato strana = this side
• na této straně = on this side

So:

• tato → nominative
• této → locative feminine singular

This is normal agreement in Czech: the demonstrative/adjective changes to match the noun’s gender, number, and case.

Because strana is a feminine noun, and in the locative singular its ending changes.

Basic form:

• strana = side

Locative singular:

• (na) straně = (on) the side

So the ending changes from -a to -ě.

This is a common pattern for many feminine nouns, though not every noun behaves exactly the same way.

Because zvuk is the subject of the sentence, and subjects are usually in the nominative case.

In this sentence:

• zvuk = the thing being described
• je lepší = is better

So:

• zvuk = nominative singular
• je agrees with it as a singular subject

That is why it stays in its basic dictionary form.

Here je is the 3rd person singular of být (to be), meaning is.

In normal standard Czech, you do include it here:

• Na této straně je zvuk lepší.

Unlike in Russian, for example, Czech normally keeps the present-tense form of to be in sentences like this.

You may sometimes see je omitted in headlines, notes, or very colloquial shorthand, but in regular full sentences it should stay.

Yes. Lepší means better, and it is the comparative form usually associated with dobrý (good).

So:

• dobrý = good
• lepší = better
• nejlepší = best

This is not a simple regular pattern like just adding one ending, so it is best learned as a form on its own.

In your sentence:

• zvuk je lepší = the sound is better

Because Czech does not have articles like English a / an / the.

So Czech often expresses the same idea without them:

• zvuk can mean sound, a sound, or the sound, depending on context
• strana can mean side, a side, or the side
• tato strana means this side, which is already specific enough

English needs articles almost all the time, but Czech does not.

Czech word order is fairly flexible, but different orders change emphasis.

Your sentence:

• Na této straně je zvuk lepší.

This naturally emphasizes on this side first, as the setting or contrast.

Other possible versions include:

• Zvuk je na této straně lepší.
  More neutral if you are mainly talking about the sound.

• Lepší je zvuk na této straně.
  More marked; sounds like a contrast or correction.

So the original sentence is perfectly natural, especially if you are comparing one side with another.

It depends on context.

Strana can mean several things, including:

• side
• page
• political party

So na této straně could mean:

• on this side
• on this page

In your sentence, if you are talking about audio, speaker balance, headphones, or stereo channels, side is the most likely meaning.

If the context were a document, website, or booklet, page could also be possible.

A natural version is:

• Na druhé straně je zvuk lepší.

Here:

• druhé = other / second in the matching case
• straně = locative singular again

So the structure is the same:

• Na této straně = on this side
• Na druhé straně = on the other side

A rough guide:

• této ≈ TAY-toh
• straně ≈ STRAH-nyeh
• zvuk ≈ zvook
• lepší ≈ LEP-shee

A few useful pronunciation notes:

• ě often creates a ye-like sound after many consonants
• š sounds like English sh
• zv at the start of zvuk can feel unusual for English speakers, so practice it slowly: z-vuk

A more syllable-by-syllable rhythm:

• Na této straně je zvuk lepší
• na TAY-toh STRAH-nyeh yeh zvook LEP-shee