Horská chata je otevřená.

• horská = mountain / mountain-related
• chata = hut, cabin, or chalet

Together, horská chata is a very natural Czech expression for a mountain hut or mountain lodge.

Because they both agree with chata, which is a feminine singular noun.

In Czech, adjectives change their endings to match the noun in:

• gender
• number
• case

Here:

• chata is feminine singular nominative
• so horská must be feminine singular nominative
• and otevřená must also be feminine singular nominative

That is why both adjectives end in -á.

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

So:

• chata je otevřená = the hut is open

This verb is normally required in a regular Czech sentence like this. Unlike subject pronouns, it is not usually left out.

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

So Horská chata je otevřená could mean:

• The mountain hut is open
• A mountain hut is open

In practice, the context tells you which one is meant. In many learning materials, it is translated as The mountain hut is open because that sounds most natural in context.

Because in this sentence, otevřená is part of the predicate: it describes the state of the hut after the verb je.

So the structure is:

• Horská chata = the subject
• je otevřená = is open

If you say otevřená horská chata, that is just a noun phrase meaning an open mountain hut. It is not the same as the full sentence The mountain hut is open.

So:

• Horská chata je otevřená. = The mountain hut is open.
• Otevřená horská chata = an open mountain hut

Yes, Czech word order is more flexible than English, but the neutral, most straightforward order here is:

Horská chata je otevřená.

Other orders are possible, but they change the emphasis. For example:

• Otevřená je horská chata.
  This sounds marked and emphasizes open.

• Je otevřená horská chata.
  This could sound like a question in speech, or a special stylistic order in writing.

So for a basic statement, Horská chata je otevřená is the best form to learn first.

It is in the nominative singular.

That is because chata is the subject of the sentence: the thing that is open.

Since horská and otevřená refer to chata, they also appear in forms that match feminine singular nominative.

They are closely related, but they are not exactly the same in style.

• otevřená is the regular adjective form
• otevřena is a short form, more formal or literary

So:

• Chata je otevřená. = the normal everyday way to say The hut is open
• Chata je otevřena. = also possible, but more formal, official, or written

For everyday conversation, otevřená is the safer choice.

A rough guide is:

HOR-skaa KHA-ta ye O-tev-rzhe-naa

A few important pronunciation points:

• ch in chata is not English ch as in chair.
  It is the throaty sound heard in German Bach or Scottish loch.

• j in je sounds like English y in yes.

• ř in otevřená is a special Czech sound.
  English speakers often approximate it as something like rzh at first, and that is fine for a beginner.

• á is a long vowel.
  So horská and otevřená both end with a long a sound.

Also, Czech stress is usually on the first syllable of each word:

• HOR-ská
• CHA-ta
• JE
• O-tevřená

Because hora means mountain, while horský / horská / horské is the adjective meaning mountain or mountain-related.

Compare:

• hora = mountain
• horská chata = mountain hut

So Czech uses an adjective here, just as English uses mountain in mountain hut, even though English mountain looks the same as the noun.