Komunitní zahrada je za domem.

Because komunitní is an adjective describing zahrada. In Czech, adjectives usually agree with the noun in gender, number, and case.

Here, zahrada is:

• feminine
• singular
• nominative (because it is the subject of the sentence)

So the adjective also appears in the feminine singular nominative form: komunitní.

This adjective happens to have the same written form in several endings, so you do not see a big change here, but it is still agreeing grammatically with zahrada.

A very common clue is the ending -a. Many Czech nouns ending in -a are feminine, and zahrada is one of them.

So:

• zahrada = feminine noun
• nominative singular = zahrada

This matters because adjectives and some other words must match its gender.

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

So:

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

In Komunitní zahrada je za domem, je links the subject with its location, just like English is.

Because za can take different cases depending on the meaning.

In this sentence, za means behind in the sense of location: the garden is already there, behind the house. For location, za takes the instrumental case.

So:

• za domem = behind the house (location)

But with movement toward a position behind something, Czech often uses the accusative:

• Jdu za dům. = I am going behind the house.

So the key contrast is:

• where? → instrumental
• to where? → accusative

Because after za in a location meaning, the noun must be in the instrumental case.

The base form is:

• dům = house

Its instrumental singular form is:

• domem

So:

• za domem = behind the house

This is something you mainly have to learn as part of Czech declension. The vowel changes too, so it is not just a simple ending added to dům.

The sentence breaks down like this:

• Komunitní zahrada = nominative singular
  This is the subject: the community garden

• je = verb
  is

• za domem = prepositional phrase with instrumental singular
  behind the house

So the overall structure is:

[subject in nominative] + [verb] + [location phrase]

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

You can say:

• Komunitní zahrada je za domem.
• Za domem je komunitní zahrada.

Both are correct. The difference is mostly in focus or emphasis.

For example:

• Komunitní zahrada je za domem.
  Neutral statement.
• Za domem je komunitní zahrada.
  Emphasizes the location behind the house.

English usually has less freedom here.

Because Czech does not have articles like English a and the.

So:

• zahrada can mean a garden or the garden
• dům can mean a house or the house

The exact meaning depends on context.

In this sentence, if the meaning shown to the learner is The community garden is behind the house, Czech expresses that without articles:

• Komunitní zahrada je za domem.

A rough English-friendly guide is:

koh-moo-neet-nee ZAHH-ra-da yeh za DOH-mem

A few useful notes:

• r in zahrada is a rolled or tapped r
• j in je sounds like English y
• á is a long vowel, so zahrada has stress on the first syllable, but the long vowel is still clearly long
• Czech stress usually falls on the first syllable of the word

A more careful approximation:

• Komunitní = KO-mu-nit-ní
• zahrada = ZAH-ra-da
• je = ye
• za domem = za DO-mem

Yes. Za is a very common Czech preposition and can have several meanings depending on context and case.

Some common meanings include:

• behind → za domem
• for / in exchange for → zaplatil za kávu = he paid for the coffee
• during / in the time of → in some expressions
• after / to get someone → jdu za kamarádem can mean I am going to see my friend

So you should not memorize za as having only one English equivalent. Its meaning depends on the whole phrase.

Normally, no. In standard Czech, the present tense of být (to be) is usually expressed, so you keep je here.

So:

• Komunitní zahrada je za domem. = correct

Leaving out je would sound incomplete in standard Czech.

You replace je with není:

• Komunitní zahrada není za domem.
  = The community garden is not behind the house.

This is the standard way to negate the verb být in the present tense.

A very useful pattern is:

[thing] + je + za + instrumental

Examples:

• Auto je za domem. = The car is behind the house.
• Pes je za stromem. = The dog is behind the tree.
• Lavička je za školou. = The bench is behind the school.

So this sentence teaches you a common location structure:

• subject in nominative
• je
• za
  • instrumental for position/location