Tržní stánek je na farmářském trhu.

Because the preposition na is expressing a location here, and after na in this meaning Czech uses the locative case.

So:

• dictionary form: farmářský trh
• after na for location: na farmářském trhu

Both words change:

• farmářský → farmářském
• trh → trhu

This is very normal in Czech: prepositions often force a particular case.

In Czech, na is commonly used for places understood as events, public spaces, or open-area destinations, and trh is one of those words. So na trhu means at the market.

A learner might expect v, because English says in the market, but Czech often chooses a different preposition.

So:

• na trhu = at the market / at the marketplace
• v trhu would not sound natural here

This is something you mostly learn as a fixed pattern: být na trhu.

Because tržní stánek is the subject of the sentence, so it stays in the nominative case:

• tržní stánek = nominative

But na farmářském trhu is a prepositional phrase showing location, so it must go into the locative:

• farmářském trhu = locative

Also, tržní is an adjective of the -í type. It does decline, but its nominative singular masculine form is already tržní. In another case, it would change too, for example:

• na tržním stánku = at the market stall

Trhu is locative singular.

The base form is:

• trh = nominative singular

After na with a location meaning, it becomes:

• na trhu = locative singular

So in this sentence, farmářském trhu is one locative phrase.

Word by word:

• tržní = market, market-related
• stánek = stall, stand, booth
• je = is
• na = on / at
• farmářském = farmers’, farmer-related, in the locative form
• trhu = market, in the locative form

A useful thing to notice is that Czech often uses adjectives where English might prefer a noun phrase. So tržní stánek is a natural way to say market stall.

They describe two different things:

• tržní stánek = a market stall
• farmářský trh = a farmers’ market

So although both words are related to markets, they are not duplicates.

• tržní comes from trh and means something like market-related
• farmářský comes from farmář and means farmer-related / farmers’

So the sentence is not repeating the same idea unnecessarily. It is saying that a certain kind of stall is located at a certain kind of market.

Both stánek and trh are masculine inanimate nouns.

That matters because adjective endings depend on gender and case:

• tržní stánek: masculine inanimate nominative singular
• na farmářském trhu: masculine inanimate locative singular

Knowing the gender helps you predict the adjective endings.

Because Czech has no articles.

So tržní stánek can mean:

• a market stall
• the market stall

The exact meaning depends on context.

English speakers often want to know which one it is, but Czech usually leaves that unstated unless something else makes it clear.

Yes. Czech word order is more flexible than English word order.

The original sentence:

• Tržní stánek je na farmářském trhu.

A different order is also possible:

• Na farmářském trhu je tržní stánek.

Both are grammatical. The difference is mainly about focus or emphasis.

• Tržní stánek je na farmářském trhu.
  starts with the stall
• Na farmářském trhu je tržní stánek.
  starts with the location

So the original order is a neutral, straightforward way to say it, but other orders can work too.

The hardest part for many learners is ř, which is a special Czech sound. In farmářském, it is in the cluster -ářs-.

A rough pronunciation guide:

• tržní ≈ trzh-nee
• stánek ≈ staa-nek
• farmářském ≈ far-maa-rzh-skem
• trhu ≈ tr-hu

A few helpful points:

• á is a long vowel
• é is a long vowel
• ř is not the same as English r
• trh has no vowel between t, r, and h, which may feel unusual to English speakers

You do not need perfect ř immediately; being understood matters more at first.

Yes. Stánek can mean several similar things depending on context, such as:

• stall
• stand
• booth
• kiosk

In this sentence, because it is connected with a market, stall is the most natural interpretation. The surrounding words help narrow the meaning.