Rovnováha a držení těla jsou důležité.

Because the subject is actually two things joined by a = and:

• rovnováha = balance
• držení těla = posture / body posture

Together they form a compound subject, so Czech uses the plural verb:

• je = is
• jsou = are

So:

• Rovnováha je důležitá. = Balance is important.
• Držení těla je důležité. = Posture is important.
• Rovnováha a držení těla jsou důležité. = Balance and posture are important.

Because důležité agrees with the whole compound subject, not just with the first noun.

The two nouns are:

• rovnováha — feminine singular
• držení — neuter singular

When Czech has a plural subject that is not masculine animate, the adjective commonly takes the plural form důležité.

Compare:

• rovnováha je důležitá — feminine singular
• držení těla je důležité — neuter singular
• rovnováha a držení těla jsou důležité — plural, non-masculine-animate

So důležité is the correct plural agreement form here.

They are in the nominative, because they are the subject of the sentence.

• rovnováha = nominative singular
• držení = nominative singular

In držení těla, only držení is the head noun of the subject. těla depends on it.

So the subject is:

• rovnováha a držení těla

and that whole subject takes the plural verb jsou.

Because těla is genitive singular of tělo = body.

The phrase držení těla literally means something like:

• holding of the body
• more naturally: posture

This kind of structure is very common in Czech: a verbal noun or abstract noun is followed by a noun in the genitive.

Examples of the same pattern:

• barva auta = the color of the car
• konec filmu = the end of the film
• držení těla = posture / the holding of the body

So těla is not plural here. It is genitive singular.

Yes, it is a very common expression meaning posture or body posture.

Word by word:

• držení comes from držet = to hold
• těla = of the body

So literally it is the holding of the body, but in normal English the best translation is usually posture.

Learners often try to understand it word-for-word, but it is best to remember držení těla as a set phrase.

Because Czech does not use articles like English does.

English distinguishes:

• the balance
• a balance
• the posture
• a posture

Czech normally just says:

• rovnováha
• držení těla

The exact meaning depends on context.

So Rovnováha a držení těla jsou důležité can naturally mean:

• Balance and posture are important
• or in some contexts The balance and posture are important

Czech leaves that unstated unless there is some special reason to make it explicit.

Yes. Czech word order is more flexible than English word order because grammatical endings show the relationships between words.

The neutral, standard order here is:

• Rovnováha a držení těla jsou důležité.

But other orders are possible for emphasis or style, for example:

• Důležité jsou rovnováha a držení těla.

That might sound more like:

• What is important is balance and posture.

So the basic meaning stays the same, but the emphasis can shift.

A very useful clue is the ending -í.

Many Czech verbal nouns ending in -ní or -tí are neuter:

• čtení = reading
• psaní = writing
• držení = holding

That is why you say:

• držení je důležité

with důležité, the neuter singular form.

So in this sentence:

• rovnováha is feminine
• držení is neuter

and together they take plural agreement.

It is an adjective, used as a predicate adjective after the verb být = to be.

Structure:

• Rovnováha a držení těla = subject
• jsou = are
• důležité = important

This is the same pattern as:

• Auto je nové. = The car is new.
• Děti jsou unavené. = The children are tired.
• Rovnováha a držení těla jsou důležité. = Balance and posture are important.

So důležité is not an adverb here; it describes the subject.

Yes, jsou is a form learners often notice.

It is pronounced approximately like soh or syoh, depending on the speaker and how carefully they speak. In normal speech, the initial j is often not strongly pronounced the way an English speaker might expect from the spelling.

So although it is written jsou, do not try to pronounce every letter separately in a very strong way.

It is the 3rd person plural of být:

• je = is
• jsou = are

The sound ř is one of the most famous difficult Czech sounds.

In držení, the cluster drže- contains ř, which is a special Czech sound somewhat between r and zh. There is no exact English equivalent.

A practical beginner approach is:

1. First get comfortable hearing it.
2. Try not to replace it with a plain English r if you can avoid it.
3. For early learning, an approximation is acceptable, but aim to improve over time.

The word is roughly pronounced like:

• dr-zheh-nyee

But that is only an approximation. The real Czech ř is a distinct sound.

In standard Czech, no. With two subjects joined by a, the normal agreement is plural:

• jsou důležité

So the correct standard sentence is:

• Rovnováha a držení těla jsou důležité.

Using je would sound ungrammatical in normal standard usage here.

Like this:

• Rovnováha je důležitá. = Balance is important.
• Držení těla je důležité. = Posture is important.

This is a good way to see the agreement clearly:

• rovnováha → feminine singular → důležitá
• držení → neuter singular → důležité
• both together → plural → důležité

That contrast helps explain why the original sentence is built the way it is.