Dobrá půda znamená dobrou úrodu.

Because the adjective has to agree with the noun in gender, number, and case.

Both půda and úroda are feminine singular nouns, but they are in different cases:

• dobrá půda = feminine singular nominative
• dobrou úrodu = feminine singular accusative

So the adjective dobrý changes like this:

• dobrá = nominative feminine singular
• dobrou = accusative feminine singular

That is why the endings are different.

Because úrodu is the direct object of the verb znamená.

In this sentence:

• Dobrá půda = the subject, so it is in the nominative
• znamená = the verb
• dobrou úrodu = what good soil “means” or “brings,” so it is the direct object and goes into the accusative

So:

• úroda = nominative form
• úrodu = accusative form

Půda is in the nominative singular.

It is the subject of the sentence: good soil is the thing doing the “meaning” or “indicating.”

That is why the phrase is dobrá půda, not dobrou půdu.

Both půda and úroda are feminine nouns.

A useful clue is that both end in -a, which often signals a feminine noun in Czech.

Because they are feminine, the adjective dobrý takes feminine endings:

• dobrá with nominative singular feminine
• dobrou with accusative singular feminine

Znamená is the 3rd person singular present tense of the verb znamenat.

So:

• znamenat = to mean, to signify
• znamená = means / signifies

It is 3rd person singular because the subject dobrá půda is singular.

Literally, znamená means means or signifies.

But in a sentence like this, it can sound a bit broader in English. Depending on context, the idea is closer to:

• Good soil means a good harvest
• Good soil leads to a good harvest
• Good soil brings a good yield

So the Czech verb is still znamenat, but the natural English interpretation may be slightly wider than just a dictionary meaning.

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

So dobrá půda can mean:

• good soil
• the good soil
• sometimes even a good soil depending on context, though in English that phrasing is less common

And dobrou úrodu can mean:

• a good harvest
• the good harvest
• good harvest/yield

Context tells you which English article is most natural.

The word order is somewhat flexible in Czech, but this sentence uses the normal, neutral order:

Dobrá půda znamená dobrou úrodu.
subject + verb + object

That is the most natural order for a simple statement.

You can change Czech word order for emphasis, contrast, or style, but then the sentence may sound marked or poetic rather than neutral.

A rough guide:

• půda ≈ POO-da
• úrodu ≈ OO-ro-doo
• dobrou ≈ DOB-roh

A few key points:

• ú and ů both represent a long u sound
• ou in Czech is a real diphthong, similar to the oa in British goat for many speakers, or like oh with a glide
• Czech stress is usually on the first syllable of the word:
  • DObrá
  • PŮda
  • ZNAmená
  • DObrou
  • Úrodu

In modern Czech pronunciation, ú and ů are pronounced the same: a long u sound.

The difference is mostly spelling and historical development.

A very useful rule for learners:

• ú is commonly used at the beginning of a word
• ů usually appears inside a word

That is why you see:

• úroda
• půda

Even though they sound the same in terms of vowel length.

Not exactly.

• úroda usually means crop, yield, harvest result
• sklizeň more often refers to the harvesting or the harvest as an event/process

So in this sentence, dobrou úrodu is about a good yield/result, which fits the meaning very well.

The dictionary form is dobrý, meaning good.

Czech adjectives are usually listed in the masculine singular nominative form, so you learn:

• dobrý = good

Then it changes depending on the noun:

• dobrá půda
• dobrou úrodu
• dobré víno
• dobrý muž

So dobrou is just one inflected form of dobrý.