Tato funkce je důležitá.

Tato means this.

Czech words for this change according to gender, number, and case. The noun funkce is feminine singular, so the correct form is tato.

A few basic nominative singular forms are:

• ten = this/that (masculine)
• ta = this/that (feminine, more like that in many contexts)
• to = this/that (neuter)
• tato = this (feminine, more explicit/literary or careful style)

So in Tato funkce, both words match: feminine singular nominative.

In Czech, every noun has a grammatical gender: masculine, feminine, or neuter.

Funkce is a feminine noun. You can see that from the way other words agree with it:

• tato funkce
• důležitá funkce

Both tato and důležitá have feminine endings because they describe funkce.

A learner should remember that grammatical gender is a property of the noun and does not always have anything to do with biological sex. A word like funkce is feminine simply because Czech grammar treats it that way.

It is in the nominative singular.

This sentence is basically:

• Tato funkce = the subject
• je důležitá = is important

Subjects are normally in the nominative case. So funkce is nominative singular feminine.

Because adjectives in Czech must agree with the noun they describe.

Here, důležitá describes funkce, which is:

• feminine
• singular
• nominative

So the adjective also has the feminine singular nominative ending -á.

Compare:

• důležitý program = an important program (masculine)
• důležitá funkce = an important function (feminine)
• důležité tlačítko = an important button (neuter)

Je is the 3rd person singular form of být = to be, so it means is.

In standard Czech, you normally keep it in sentences like this:

• Tato funkce je důležitá. = This function is important.

Unlike Russian, Czech usually does not drop the present-tense to be in standard neutral sentences.

In very informal styles, headlines, notes, or certain spoken contexts, parts of sentences may be omitted, but for a normal full sentence, je belongs there.

Czech has no articles like English a/an/the.

So funkce can mean:

• a function
• the function
• just function

The exact meaning depends on context.

In this sentence, tato already makes it specific:

• Tato funkce je důležitá. = This function is important.

So Czech does not need a separate word for the.

Not always. Czech has several ways to express this/that, and usage can depend on style and emphasis.

For feminine singular nominative, you may see:

• tato = this
• ta = that, but also often used where English would say this depending on context

For learners, a useful rule is:

• tato is the clearer, more explicit form for this
• ta is shorter and very common in everyday speech, but can feel more like that or just a weaker demonstrative

So Tato funkce je důležitá is a very natural textbook-style sentence meaning This function is important.

A rough pronunciation guide for an English speaker is:

• Tato ≈ TAH-to
• funkce ≈ FOONK-tse
• je ≈ yeh
• důležitá ≈ DOO-zhe-li-taa

A few important sounds:

• j in Czech sounds like English y in yes
• c sounds like ts
• ž sounds like the s in measure
• á is a long vowel
• ů is pronounced like a long ú, roughly oo

So důležitá has long vowels in dů- and -tá.

Ů represents a long u-sound, pronounced roughly like oo in food, but clearly long.

So:

• u = short vowel
• ú / ů = long vowel

In modern pronunciation, ú and ů are pronounced the same. The difference is mainly historical and orthographic.

So in důležitá, the first syllable is pronounced with a long vowel: dů-.

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

The neutral word order here is:

• Tato funkce je důležitá.

But other orders are possible for emphasis, for example:

• Funkce je důležitá. = The function is important.
• Důležitá je tato funkce. = It is this function that is important.
• Tato funkce důležitá je. = possible with special emphasis or contrast

Even though word order can change, the neutral basic version for learners is the one you were given.

In this sentence, důležitá is not directly attached to the noun inside a noun phrase. It is part of the predicate:

• Tato funkce = subject
• je důležitá = predicate (is important)

If you put the adjective directly before the noun, you get a noun phrase:

• důležitá funkce = an important function

So compare:

• Tato funkce je důležitá. = This function is important.
• Tato důležitá funkce... = This important function...

Both are correct, but they have different structures.

Its form shows that it is an adjective.

In this sentence, důležitá agrees with funkce, so it behaves like an adjective describing a noun.

The related noun is:

• důležitost = importance

So:

• důležitá = important
• důležitost = importance

Czech often uses different endings to mark different parts of speech very clearly.

Yes, you could, but the meaning or tone may shift slightly depending on context.

• Tato funkce je důležitá. = This function is important.
• Ta funkce je důležitá. = That function is important / that function is the important one / sometimes colloquially this function, depending on context

For a learner, tato is the safest choice when you clearly want this.

In everyday speech, native speakers often use shorter forms like ta, but the exact meaning depends more on situation and intonation.

Yes. It is a fully normal, standard Czech sentence.

It contains:

• a subject: Tato funkce
• a verb: je
• a predicate adjective: důležitá

So it is a very useful model sentence for beginners, because it shows several key Czech patterns at once:

• demonstrative agreement: tato
• noun gender: funkce is feminine
• verb to be: je
• adjective agreement: důležitá