Korzeń jest zdrowy.

A natural pronunciation is approximately:

KOH-zhen yest ZDRO-vih

A bit more precisely:

• ko- as in coffee without the final ee
• -rzeń: the rz here sounds like Polish ż, similar to the s in measure
• ń is a soft n, like the ny in canyon
• jest is pronounced almost like yest
• zdrowy has stress on the first syllable: ZDRO-wy

In normal Polish, stress usually falls on the second-to-last syllable, so:

• KO-rzeń
• JEST
• zdro-WY? Actually because zdrowy has two syllables, the stress is on the first: ZDRO-wy

Korzeń is a noun in the nominative singular. It is the subject of the sentence.

So grammatically:

• korzeń = the thing being talked about
• jest = is
• zdrowy = healthy

This is a very standard Polish sentence pattern:

noun + jest + adjective

Korzeń is masculine.

That matters because in Polish, adjectives must agree with the noun in:

• gender
• number
• case

Since korzeń is:

• masculine
• singular
• nominative

the adjective must also be in the masculine singular nominative form:

• zdrowy = masculine
• compare:
  • zdrowa = feminine
  • zdrowe = neuter

So korzeń jest zdrowy is correct because zdrowy matches korzeń.

Because korzeń is a masculine noun.

In Polish, adjective endings change depending on the noun:

• zdrowy = masculine
• zdrowa = feminine
• zdrowe = neuter

Examples:

• kobieta jest zdrowa = the woman is healthy
• dziecko jest zdrowe = the child is healthy
• korzeń jest zdrowy = the root is healthy

Even though English adjectives do not change, Polish adjectives do.

In a normal, complete sentence like this, yes.

Jest is the 3rd person singular form of być (to be), so it means is.

• Korzeń jest zdrowy = normal, standard sentence
• Korzeń zdrowy = possible in notes, headlines, or very compressed style, but not the usual full sentence

So for learners, it is best to treat jest as required here.

Because Polish has no articles.

English says:

• a root
• the root

Polish just says:

• korzeń

Whether it means a root, the root, or simply root depends on context.

So Korzeń jest zdrowy could mean:

• The root is healthy
• A root is healthy

Usually the broader context tells you which one is intended.

Not only. Korzeń can mean:

• a root of a plant
• the root of a problem or idea
• a mathematical root

However, with zdrowy (healthy), the most natural interpretation is a literal, physical root, especially a plant root.

So in this sentence, learners would normally understand korzeń in the biological sense.

Yes. Polish word order is more flexible than English word order.

The neutral order here is:

Korzeń jest zdrowy.

But other orders are possible for emphasis, for example:

• Zdrowy jest korzeń.
• Jest zdrowy korzeń. — less neutral, more context-dependent

Even when the order changes, the endings still show the grammar.

For learners, though, Korzeń jest zdrowy is the best basic pattern to remember.

It is also in the nominative singular masculine.

Although zdrowy is an adjective, it matches the noun korzeń, so it takes the same case here.

Why nominative? Because korzeń is the subject, and predicate adjectives after jest normally agree with the subject.

So:

• korzeń = nominative singular masculine
• zdrowy = nominative singular masculine

Yes, it is still masculine.

Many masculine Polish nouns end in a consonant, and ń is a consonant too, just a soft one.

So even though korzeń may not look like the most typical masculine noun to an English speaker, it behaves as masculine.

You can see that in related forms too:

• korzeń = nominative singular
• korzenia = genitive singular
• korzenie = nominative plural

The important beginner point is: memorize the noun together with its gender.

It can definitely be used for things like roots.

In Polish, zdrowy is used not only for people but also for:

• body parts
• plants
• animals
• food in some contexts
• abstract things in expressions like zdrowy rozsądek (common sense, literally healthy reason/sense)

So korzeń jest zdrowy sounds natural if you are talking about a plant, gardening, agriculture, or biology.

Two important things:

• rz usually sounds like ż
• ń is a soft n

So korzeń is not pronounced the way an English speaker might guess from the spelling.

Also, Polish spelling often preserves historical distinctions that are not always heard clearly in modern pronunciation. That is why rz and ż can sound the same in many words, even though they are written differently.

For learning this word, the key thing is simply:

• recognize korzeń
• remember its pronunciation
• remember that the final ń is soft

You would change both the noun and the adjective to plural:

Korzenie są zdrowe.

Changes:

• korzeń → korzenie = roots
• jest → są = are
• zdrowy → zdrowe = healthy, plural non-masculine-personal

This is a good example of how Polish words change to show grammar, instead of relying as much on fixed word order as English does.