Dobra drenaža čuva korijen biljke.

Because drenaža is a feminine singular noun, and the adjective has to agree with it in gender, number, and case.

• dobar = masculine singular
• dobra = feminine singular
• dobro = neuter singular

So:

• dobra drenaža = good drainage

This is basic adjective–noun agreement in Croatian.

Drenaža is in the nominative singular because it is the subject of the sentence — the thing doing the action.

In Dobra drenaža čuva korijen biljke, the drainage is what protects/preserves the root.

So:

• dobra drenaža = subject, nominative
• čuva = protects / preserves
• korijen biljke = object phrase

Here korijen is the direct object of čuva, so it is in the accusative singular.

The important point is that masculine inanimate nouns in Croatian often have the same form in nominative and accusative singular.

So:

• nominative: korijen = root
• accusative: korijen = root

That is why the form does not visibly change here.

Biljke is in the genitive singular and means of the plant.

So:

• korijen biljke = the root of the plant

This is a very common Croatian structure: one noun followed by another noun in the genitive to show possession or connection.

Compare:

• list biljke = the leaf of the plant
• boja cvijeta = the color of the flower

So biljke is not the object of the verb; it belongs to korijen.

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

So Dobra drenaža čuva korijen biljke can be understood as something like:

• Good drainage protects the plant’s root
• Good drainage protects a plant root
• Good drainage protects the root of the plant

The exact article choice is supplied by context when translating into English.

Čuva is the 3rd person singular present tense of čuvati.

It can mean:

• protects
• guards
• keeps safe
• sometimes preserves

In this sentence, protects is the most natural English choice.

So:

• čuvam = I protect / keep
• čuvaš = you protect
• čuva = he/she/it protects

Since dobra drenaža is singular, the verb is also singular: čuva.

Yes. Croatian word order is more flexible than English because case endings show the grammatical roles.

The neutral, straightforward order here is:

• Dobra drenaža čuva korijen biljke.

But other orders are possible, for example:

• Korijen biljke čuva dobra drenaža.
• Dobra drenaža korijen biljke čuva.

These alternatives may sound more marked, literary, or emphatic depending on context. For a learner, the original sentence is the safest and most natural basic order.

Because biljke can represent more than one grammatical form, and you identify the meaning from context.

Biljke can be:

• genitive singular of biljka = of the plant
• nominative plural = plants
• accusative plural = plants

In this sentence, korijen biljke is a noun + genitive structure, so biljke is understood as genitive singular:

• root of the plant

If it meant plants as a subject, the sentence structure would be different.

They are related, but korijen biljke is much more normal and neutral.

• korijen biljke = the root of the plant
• biljčin korijen = the plant’s root

Croatian can form possessive adjectives from some nouns, but with many nouns, especially in ordinary factual statements, the genitive construction is more common and more natural.

So a learner should strongly prefer:

• korijen biljke

A few letters may stand out:

• č in čuva = like ch in church, but usually a bit harder
• ž in drenaža = like the s in measure
• j in korijen and biljke = like English y in yes

A rough pronunciation guide:

• dobra ≈ DOH-bra
• drenaža ≈ dreh-NA-zha
• čuva ≈ CHOO-va
• korijen ≈ KO-ri-yen
• biljke ≈ BEEL-yke

These are only approximations, but they help an English speaker get started.

It is a normal Croatian word, but it is also clearly an international/borrowed-type word, similar to English drainage.

Learners often notice that some Croatian words look familiar because they come from widely shared European vocabulary. Even if the origin is borrowed, drenaža is fully usable Croatian.

In context, it refers to drainage, especially in gardening, soil, medicine, engineering, and similar areas.

The sentence follows a simple pattern:

• Adjective + noun = Dobra drenaža
• Verb = čuva
• Object + genitive modifier = korijen biljke

So structurally it is:

• [Subject] [Verb] [Object]
• Good drainage protects the root of the plant

This is a very useful pattern to learn because you can build many similar sentences with it.