Kauce je vysoká.

Because Czech adjectives must agree with the noun they describe.

Here, kauce is a feminine singular noun, so the adjective also has to be feminine singular:

• masculine: vysoký
• feminine: vysoká
• neuter: vysoké

So:

• Kauce je vysoká. = feminine singular

Yes, kauce is feminine.

A learner might guess that from the adjective agreement in vysoká, but you also simply learn the noun with its gender. Czech noun endings can help, but they are not always completely reliable on their own.

With kauce, the important thing is:

• ta kauce = feminine
• therefore: vysoká kauce, kauce je vysoká

So even though the noun ends in -e, it is feminine.

Je is the 3rd person singular present tense of být (to be).

So:

• já jsem = I am
• ty jsi = you are
• on/ona/ono je = he/she/it is

In Kauce je vysoká, je means is.

Normally, in a standard sentence like this, no. You usually keep je.

So the normal sentence is:

• Kauce je vysoká.

Leaving it out would sound incomplete in ordinary Czech.

In some special styles, such as headlines, notes, or very informal speech, parts of sentences may be omitted, but for a learner the safe rule is:

• with this kind of sentence, use je

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

So:

• Kauce je vysoká. can mean The deposit is high or A deposit is high, depending on context.
• In real usage, context tells you which is meant.

If Czech speakers want to make something more specific or point to it, they may use words like:

• ta kauce = that deposit / the deposit (depending on context)

But there is no direct article system like in English.

Kauce is in the nominative, because it is the subject of the sentence.

The adjective vysoká is also in the nominative feminine singular, because after být (to be) Czech normally uses a predicate adjective that agrees with the subject.

So grammatically:

• kauce = nominative singular
• vysoká = nominative singular feminine

It can mean high, and that is the natural meaning here.

The adjective vysoký / vysoká / vysoké often means:

• tall for people or things with height
• high for levels, amounts, prices, fees, deposits, etc.

So in this sentence, vysoká kauce means a high deposit, not a physically tall one.

Yes, Czech word order is more flexible than English, but the neutral version is:

• Kauce je vysoká.

Other word orders are possible, but they change the emphasis:

• Vysoká je kauce. = marked, unusual, with special emphasis
• Je vysoká, ta kauce. = more conversational, focusing on how high it is

For learners, Kauce je vysoká is the best basic pattern.

A simple approximation is:

• KAU-tse ye VY-so-kah

A few useful pronunciation points:

• c in Czech is pronounced ts
• je sounds like ye
• stress is usually on the first syllable of each word:
  • KAU-ce
  • je
  • VY-so-ká
• the final á is a long vowel

So vysoká has a longer last vowel than vysoka would.

Because Czech usually does not use subject pronouns unless they are needed for emphasis or contrast.

English needs it is, but Czech can simply say:

• Kauce je vysoká.

The noun kauce already tells you what the subject is, so no extra pronoun is needed.

Yes. That is completely possible.

• Kauce je vysoká. = neutral, general
• Ta kauce je vysoká. = that deposit / the deposit is high, often more specific or contrastive

Adding ta can make the sentence feel more definite or point to a particular deposit that is already known from the context.

The base adjective changes to match the noun:

• masculine singular: vysoký
• feminine singular: vysoká
• neuter singular: vysoké

Examples:

• Poplatek je vysoký. = The fee is high.
• Kauce je vysoká. = The deposit is high.
• Nájemné je vysoké. = The rent is high.

This is one of the most important patterns in Czech grammar: adjectives agree with nouns in gender, number, and case.