Skleník je starý.

Czech has no articles, so it does not use separate words for a/an or the.

So Skleník je starý. can mean:

• The greenhouse is old.
• A greenhouse is old.

Which one is meant depends on the context.

Je 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 Skleník je starý., je means is.

Starý is the masculine singular form of the adjective old.

It matches skleník, which is:

• masculine
• singular
• in the nominative case

Czech adjectives must agree with the noun they describe.

Here are some matching forms:

• starý skleník = old greenhouse
• stará zahrada = old garden
• staré auto = old car
• staré skleníky = old greenhouses

So the ending -ý is used because skleník is a masculine singular noun.

In Czech, nouns belong to grammatical genders, and you usually learn the gender together with the word.

Skleník is masculine inanimate.

One clue is its typical dictionary form ending in a consonant: skleník. Many Czech masculine nouns end in a consonant, though you still need to learn each noun's gender because there are exceptions.

Because skleník is masculine, the adjective also takes a masculine form: starý.

It is in the nominative case, because it is the subject of the sentence.

In Skleník je starý.

• Skleník = subject
• je starý = predicate meaning is old

The adjective starý is also in the nominative because predicate adjectives after být normally agree with the subject.

No. In this sentence, a subject pronoun is not needed.

Czech often leaves out personal pronouns unless they are needed for emphasis or contrast.

So the normal sentence is simply:

• Skleník je starý.

You could say On je starý only if it/he is already clear from context, but that would usually mean He/it is old, not specifically The greenhouse is old.

Yes. Czech word order is more flexible than English, but the most neutral order here is:

• Skleník je starý.

You may also see:

• Starý je skleník.
• Je starý skleník. (less neutral, depends on context)

Changing the word order usually changes emphasis, not the basic meaning.

For a beginner, Skleník je starý. is the safest and most natural form.

A simple pronunciation guide is:

• Skleník ≈ SKLEH-neek
• je ≈ ye
• starý ≈ STA-ree

A few notes:

• í and ý indicate a long vowel
• j in Czech is pronounced like English y in yes
• stress in Czech is usually on the first syllable of each word:
  • SKLEník
  • je
  • STArý

So the sentence sounds roughly like:

SKLEH-neek ye STA-ree

These are different forms of the same adjective, chosen to match the noun’s gender and number.

Examples:

• starý skleník = old greenhouse (masculine singular)
• stará kniha = old book (feminine singular)
• staré auto = old car (neuter singular)
• staré skleníky = old greenhouses (plural, in many contexts)

So in Skleník je starý., starý is used because skleník is masculine singular.

In this sentence, starý most naturally means old in age or not new.

So Skleník je starý. means the greenhouse is old, probably because it has existed for a long time or is worn with age.

Depending on context, starý can sometimes also mean:

• longtime
• former
• old-fashioned

But in a simple sentence like this, the basic meaning is just old.

The accent marks show vowel length, not stress.

• í = a long i
• ý = a long y sound

In modern Czech pronunciation, i and y are pronounced the same, and í and ý are also pronounced the same as each other, except that they are long.

So:

• i / y = short vowel
• í / ý = long vowel

These marks are important in spelling and grammar, so you should always write them.

In normal standard Czech, no—you should keep je in this sentence.

So:

• Skleník je starý. = correct
• Skleník starý. = not a normal complete standard sentence

Unlike Russian, for example, Czech does use the present tense of to be in sentences like this.