Ovo je greška u zalijevanju.

Ovo means this and is the neuter singular form used when you are pointing to or identifying something in a general way.

In sentences like this, Croatian often uses ovo je ... = this is ...

Examples:

• Ovo je kuća. = This is a house.
• Ovo je problem. = This is a problem.
• Ovo je greška. = This is a mistake.

Even though greška is feminine, ovo stays neuter here because it refers to this thing / this situation, not because it has to agree with greška.

Je is the 3rd person singular present tense of biti = to be.

So:

• ovo = this
• je = is
• greška = a mistake

Together:

• Ovo je greška = This is a mistake

Croatian usually includes je in this kind of sentence, just like English includes is.

Here greška is in the nominative singular because it is the predicate noun after je in an identifying sentence.

Structure:

• Ovo je greška. = This is a mistake.

The basic dictionary form is greška, and that is the form used here.

Other forms would appear in other grammatical roles:

• Vidim grešku. = I see the mistake. → accusative
• Nema greške. = There is no mistake. → genitive
• O grešci govorimo. = We are talking about the mistake. → locative

Zalijevanju is in the locative singular.

That is because the preposition u often takes the locative when it means in.

So:

• u zalijevanju = in watering

The noun is:

• zalijevanje = watering

Its locative singular form is:

• zalijevanju

This is a very common pattern:

• u radu = in work
• u učenju = in learning
• u pisanju = in writing
• u zalijevanju = in watering

Zalijevanje is a verbal noun formed from the verb zalijevati / zaliti, meaning to water or to pour over, depending on context.

As a noun, zalijevanje means:

• watering
• the act/process of watering

This is similar to English watering in phrases like watering plants.

So in the sentence:

• greška u zalijevanju literally means a mistake in watering
• in more natural English, it could also mean a watering mistake or a mistake while watering

U + locative here expresses the idea in the process/activity of doing something.

So:

• greška u zalijevanju = a mistake in watering

Croatian can also use other prepositions in similar contexts:

• pri zalijevanju = during/while watering
• kod zalijevanja = in the course of watering / when watering

But u zalijevanju is a normal and natural way to say it.

Very roughly:

• u zalijevanju focuses on the activity itself
• pri zalijevanju often sounds like while watering / during watering

In many everyday situations, both can be understandable, but u zalijevanju works well here.

Croatian has no articles like a or the.

So greška can mean:

• a mistake
• the mistake

The exact meaning depends on context.

In this sentence, English will usually translate it as:

• This is a mistake in watering or
• This is the mistake in watering

Usually, without special context, English speakers will understand it more naturally as a mistake.

Yes, Croatian word order is more flexible than English word order.

The neutral order here is:

• Ovo je greška u zalijevanju.

But other orders are possible for emphasis, for example:

• Greška je u zalijevanju. = The mistake is in the watering.
• U zalijevanju je greška. = The mistake is in the watering process.

These alternatives shift the focus a bit. For a learner, the original version is the safest and most neutral one.

A helpful approximate pronunciation is:

za-lee-yeh-VA-nyoo

A few notes:

• j in Croatian is pronounced like English y in yes
• lj is a single sound, similar to the lli in million for many English speakers
• the stress is not usually marked in normal writing

So:

• zalijevanje ≈ za-lee-yeh-VA-nyeh
• zalijevanju ≈ za-lee-yeh-VA-nyoo

Yes. Zalijevanje is the standard Ijekavian form, which is used in standard Croatian.

You may also see related forms in other varieties of the language area, such as:

• zalivanje instead of zalijevanje

For Croatian, zalijevanje is the expected standard form.

So if you are learning Croatian specifically, use:

• zalijevati
• zalijevanje
• u zalijevanju

Yes. Greška and pogreška both mean mistake/error.

In many situations they are very close in meaning:

• Ovo je greška u zalijevanju.
• Ovo je pogreška u zalijevanju.

Both are understandable and correct. In everyday speech, many speakers use greška very often because it is shorter and very common.

If you want to say These are mistakes in watering, you would say:

• Ovo su greške u zalijevanju.

Changes:

• je → su because the verb is now plural
• greška → greške because the noun is now plural

You may also hear:

• To su greške u zalijevanju.

Both ovo and to can appear in identifying sentences, depending on context.