Izvadak je čitljiv.

It is in the nominative singular.

In this sentence, izvadak is the subject of the sentence — the thing being described as čitljiv.

A simple way to see it:

• Izvadak = the excerpt / extract
• je čitljiv = is readable / legible

Because it is the subject, nominative is the expected case.

Croatian does not have articles.

So where English says:

• the excerpt is readable
• an excerpt is readable

Croatian can simply say:

• Izvadak je čitljiv.

Whether it means the, a, or just a general statement depends on context.

Je means is.

It is the 3rd person singular present form of the verb biti = to be.

So:

• ja sam = I am
• ti si = you are
• on/ona/ono je = he/she/it is

In Izvadak je čitljiv, je links the subject izvadak with the adjective čitljiv, just like is in English.

Because je is a clitic in Croatian.

Clitics are short, unstressed words that usually go in the second position of the sentence or clause. That means they often come after the first word or first phrase.

So the neutral order is:

• Izvadak je čitljiv.

You should not think of je as a word that can freely go anywhere. Its position is much more restricted than English is.

Čitljiv is an adjective.

It means readable or legible, depending on context.

In this sentence, it is a predicate adjective — it comes after je and describes the subject:

• Izvadak je čitljiv. = The excerpt is readable.

But it can also be used directly before a noun:

• čitljiv izvadak = a readable excerpt

Because it has to agree with izvadak.

Croatian adjectives agree with the noun they describe in:

• gender
• number
• case

Here, izvadak is:

• masculine
• singular
• nominative

So the adjective is also:

• čitljiv = masculine singular nominative

Compare:

• Knjiga je čitljiva. = The book is readable.
  (knjiga is feminine)
• Pismo je čitljivo. = The letter/text is readable.
  (pismo is neuter)

Yes.

It is related to čitati = to read.

The adjective čitljiv basically means something like:

• able to be read
• easy enough to read
• legible/readable

The suffix -ljiv often creates adjectives with a meaning like able to be X-ed or suitable for X.

So for a learner, it is useful to connect:

• čitati = to read
• čitljiv = readable / legible

Yes.

Čitljiv can cover both ideas:

• readable = easy enough to read, understandable as text
• legible = clear enough to read visually

Which English word is best depends on context.

For example:

• if you are talking about handwriting, print quality, or whether letters are clear, legible may fit well
• if you are talking about style or difficulty, readable may fit better

So čitljiv is a fairly flexible adjective in English translation.

Yes, but Izvadak je čitljiv is the most neutral order.

Croatian word order is more flexible than English, but not random. Because je is a clitic, it still tends to stay in second position.

For example, you may also hear:

• Čitljiv je izvadak.

That version gives more emphasis to čitljiv.

But for a basic, neutral statement, Izvadak je čitljiv is the safest pattern to learn.

A rough English-friendly guide is:

• Izvadak ≈ EEZ-va-dak
• je ≈ ye
• čitljiv ≈ CHEET-lyiv

A few important sound notes:

• č sounds like ch in church
• j sounds like y in yes
• lj is a single Croatian sound, roughly similar to the lli sound many English speakers hear in million, though not exactly the same

So the sentence is pronounced roughly like:

• EEZ-va-dak ye CHEET-lyiv