To je důležitá skutečnost.

In this sentence, to is a demonstrative pronoun. It often corresponds to this, that, or sometimes just it in English.

So To je ... is a very common Czech way to say:

• This is ...
• That is ...
• It is ...

Which English translation fits best depends on context.

Because důležitá has to agree with skutečnost.

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

• gender
• number
• case

Skutečnost is a feminine singular noun in the nominative, so the adjective must also be feminine singular nominative:

• masculine: důležitý
• feminine: důležitá
• neuter: důležité

So:

• důležitá skutečnost = an important fact

Yes, it is feminine.

A lot of Czech feminine nouns do end in -a, but not all of them. Skutečnost belongs to a common feminine noun pattern that includes words ending in a consonant, especially abstract nouns such as:

• radost = joy
• možnost = possibility
• společnost = company / society
• skutečnost = fact / reality

So even though it does not look feminine to an English speaker at first, it is grammatically feminine.

It is in the nominative.

With the verb být (to be), Czech normally uses the nominative for the predicate noun in simple statements like this:

• To je skutečnost.
• To je problém.
• To je pravda.

So both důležitá and skutečnost are nominative singular feminine here.

Because Czech has no articles.

English says:

• a fact
• the fact

Czech usually just says:

• skutečnost

Whether it means a fact, the fact, or just fact/reality is understood from context.

So To je důležitá skutečnost can mean:

• That is an important fact
• This is an important fact
• sometimes even That is the important fact, if the context makes that clear

Yes. Skutečnost can mean:

• fact
• reality
• actuality

In this sentence, fact is the most natural translation.

A useful contrast is:

• fakt = fact, often more colloquial or direct
• skutečnost = fact / reality, often a bit more formal or abstract

So To je důležitá skutečnost sounds a little more formal than To je důležitý fakt.

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

The relevant forms are:

• jsem = I am
• jsi / jseš = you are
• je = he / she / it is

So:

• To je ... = That/This is ...

This word order is the most neutral and natural one.

• To je důležitá skutečnost.

Czech word order is more flexible than English, but changes in word order often change emphasis rather than basic meaning.

For example:

• To je důležitá skutečnost. = neutral
• Je to důležitá skutečnost. = also very normal, often with slightly different information focus
• Důležitá skutečnost to je. = marked, emphasizing important fact

So yes, other orders are possible, but the given one is the standard neutral version.

Both are common and often translate the same way.

• To je důležitá skutečnost.
• Je to důležitá skutečnost.

Both can mean That/This is an important fact.

The difference is mostly about information structure and emphasis:

• To je ... often starts with the thing being identified
• Je to ... can sound slightly more like a general statement about it

In many everyday situations, they are interchangeable.

A rough pronunciation guide is:

to ye doo-leh-zhi-taa skoo-tehch-nost

A few key points:

• j is pronounced like English y in yes
• ů is a long oo sound
• ž sounds like the s in measure
• č sounds like ch in church
• á is a long a

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

• TO je DŮležitá SKUtečnost

Důležitý means important.

You will see different endings depending on the noun:

• důležitý = masculine
• důležitá = feminine
• důležité = neuter

Examples:

• důležitý problém = an important problem
• důležitá otázka = an important question
• důležité rozhodnutí = an important decision

So in your sentence, důležitá is simply the feminine form of important.

Yes.

• To je důležitá skutečnost. = This/That is an important fact.
• Tohle je důležitá skutečnost. = This is an important fact.
• Tamto je důležitá skutečnost. = That over there is an important fact.

To is more general and very common. Tohle is more specifically this, and tamto is more specifically that over there.

It sounds neutral to slightly formal.

That is mainly because of skutečnost, which is a bit more formal or abstract than fakt.

Compare:

• To je důležitá skutečnost. = neutral / slightly formal
• To je důležitý fakt. = a bit more direct and everyday

Both are correct, but they have slightly different style and nuance.