Energetický štítek je na úsporném spotřebiči.

Because it is the subject of the sentence — the thing being talked about.

• energetický štítek = the energy label
• je = is
• na úsporném spotřebiči = on the energy-efficient appliance

In Czech, the subject is usually in the nominative case, so both words stay in their basic dictionary form:

• štítek = nominative singular
• energetický agrees with štítek, so it is also nominative singular masculine

Because after na, Czech uses different cases depending on the meaning.

Here, na means on in the sense of location (where something is), so it takes the locative case:

• na úsporném spotřebiči = on the energy-efficient appliance

Compare:

• je na spotřebiči = it is on the appliance → location → locative
• dám štítek na spotřebič = I’ll put the label onto the appliance → movement toward a destination → accusative

So in your sentence, the label is already there, which is why na is followed by the locative.

Because spotřebič is in the locative singular after na.

Its nominative form is:

• spotřebič = appliance

But after na for location, it changes to:

• na spotřebiči = on the appliance

This is a normal case ending for many masculine nouns of this type.

So:

• nominative: spotřebič
• locative singular: spotřebiči

Because the adjective has to agree with the noun it describes.

The noun spotřebiči is:

• masculine
• singular
• locative

So the adjective must also be:

• masculine
• singular
• locative

That gives:

• úsporný spotřebič = an energy-efficient appliance
• na úsporném spotřebiči = on an energy-efficient appliance

This agreement between adjective and noun is one of the most important patterns in Czech grammar.

Je is the 3rd person singular form of the verb být (to be).

So:

• je = is

In this sentence:

• Energetický štítek je na úsporném spotřebiči.
• The energy label is on the energy-efficient appliance.

Czech uses je here just like English uses is.

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

So:

• energetický štítek can mean an energy label or the energy label
• úsporný spotřebič can mean an energy-efficient appliance or the energy-efficient appliance

The exact meaning depends on the context.

English learners often want to add an article mentally, but in Czech you usually just leave it out.

No, Czech word order is fairly flexible, although this sentence uses a very neutral, natural order:

• Energetický štítek je na úsporném spotřebiči.

This is basically:

• subject + verb + place

Because Czech marks grammatical roles with case endings, you can often move parts around for emphasis:

• Na úsporném spotřebiči je energetický štítek.
• Energetický štítek na úsporném spotřebiči je. (possible, but less neutral and more marked)

The original version is the most straightforward and natural for a learner.

Na usually means on or on top of, while v usually means in / inside.

So here:

• na úsporném spotřebiči = on the appliance

If you said:

• v spotřebiči

that would mean:

• in the appliance / inside the appliance

Since a label is attached to the outside surface, na is the correct preposition.

Because Czech energetický often means energy-related, not just energetic in the English personality sense.

So:

• energetický štítek = energy label
• energetická krize = energy crisis

Even though it looks similar to English energetic, the meaning here is more technical: it relates to energy use or energy efficiency.

Úsporný means something like:

• economical
• efficient
• energy-saving

In this sentence, úsporný spotřebič is an appliance that uses less energy, so energy-efficient appliance is the most natural translation.

The basic idea of úsporný is saving resources — often electricity, money, fuel, or time depending on context.

You usually learn a noun’s gender together with its basic form.

Štítek is masculine inanimate. One clue is that many masculine nouns end in a consonant, as štítek does.

Because it is masculine singular nominative, the adjective also takes the masculine nominative ending:

• energetický štítek

If the noun had a different gender, the adjective would change too. For example:

• masculine: energetický štítek
• feminine: energetická značka
• neuter: energetické označení

Spotřebiči is roughly pronounced like:

• spo-trzhe-bi-chi

The hardest sound for many learners is ř, which is a special Czech sound with no exact English equivalent. It is somewhat like a rolled or buzzing r combined with a zh sound.

Very roughly:

• ř in spotřebič sounds a bit like the s in measure mixed with an r

You do not need perfect ř immediately. It is better to say it clearly and consistently than to worry about sounding native right away.

Grammatically, Czech word order is flexible enough that this is possible, but it sounds unnatural in normal speech.

The normal phrase is:

• na úsporném spotřebiči

In Czech, adjectives usually come before the noun they describe, just as in English:

• úsporný spotřebič
• energetický štítek

Putting the adjective after the noun is usually poetic, highly marked, or stylistically unusual. So learners should stick with:

• na úsporném spotřebiči