Moja radna biografija je spremna.

Because biografija is a feminine singular noun, and the possessive adjective moj (my) has to agree with it.

Agreement here is:

• moj = masculine singular
• moja = feminine singular
• moje = neuter singular

So:

• moj pasoš = my passport
• moja biografija = my biography / my CV
• moje pismo = my letter

Since the noun is biografija, you need moja.

For the same reason: radna must agree with biografija.

The adjective radan/radna/radno means something like work-related or employment-related here. Since biografija is feminine singular, the adjective also takes the feminine singular form:

• radni = masculine
• radna = feminine
• radno = neuter

So:

• radna biografija = work biography / resume / CV

This is standard adjective-noun agreement in Serbian.

Yes, in practice it refers to a resume/CV, especially in a formal or semi-formal context.

Literally, radna biografija is something like work biography or employment biography, but natural English translation is usually:

• resume
• CV

In modern Serbian, people also very often just say CV:

• Moj CV je spreman. = My CV is ready.

So radna biografija is understandable and correct, but CV is also extremely common.

It is in the nominative singular.

That is because biografija is the subject of the sentence:

• Moja radna biografija = the thing being talked about
• je spremna = is ready

So the whole structure is:

• [subject in nominative] + je + adjective

Here:

• Moja radna biografija = subject
• je = is
• spremna = ready

Je is the 3rd person singular present of biti (to be), so it means is.

• Moja radna biografija je spremna. = My resume is ready.

In standard Serbian, you normally keep je in this kind of sentence. Leaving it out would usually sound incomplete, nonstandard, or like very informal shorthand.

So for a normal full sentence, use:

• je

not:

• Moja radna biografija spremna. (not standard as a neutral full sentence)

Because spremna is an adjective, and it also has to agree with the noun biografija, which is feminine singular.

The adjective spreman means ready, and its forms include:

• spreman = masculine singular
• spremna = feminine singular
• spremno = neuter singular

So:

• Dokument je spreman. = The document is ready.
  (dokument is masculine)

• Biografija je spremna. = The biography/CV is ready.
  (biografija is feminine)

The given word order is the most neutral and natural for a statement:

• Moja radna biografija je spremna.

But Serbian word order is fairly flexible, so other versions are possible depending on emphasis.

For example:

• Radna biografija mi je spremna. = My resume is ready.
  (with a slightly different focus and using mi = to me / my, in a natural possessive style)

• Spremna je moja radna biografija.
  This is possible, but sounds marked or emphatic.

For learners, the safest neutral pattern is:

• Subject + je + adjective

Yes, absolutely.

That is often more natural in everyday modern usage:

• Moj CV je spreman. = My CV is ready.

Notice the grammar changes:

• CV is treated as masculine
• so you use moj instead of moja
• and spreman instead of spremna

Compare:

• Moja radna biografija je spremna.
• Moj CV je spreman.

Both are correct; the second is often more common in speech.

By itself, biografija usually means biography in the broad sense: a description of someone’s life.

But when you add radna, it specifically points toward a work/employment biography, so it can mean a resume/CV.

So:

• biografija = biography
• radna biografija = work biography / CV / resume

Without radna, the meaning is more general and may not automatically suggest a job application document.

A rough pronunciation guide for an English speaker would be:

• Moja ≈ MOH-yah
• radna ≈ RAHD-nah
• biografija ≈ bee-oh-grah-FEE-yah
• je ≈ yeh
• spremna ≈ SPREM-nah

A few useful notes:

• j in Serbian is pronounced like English y in yes
• r is rolled or tapped
• stress is not usually marked in normal writing, so learners usually just imitate native speech

No. The feminine forms here do not describe the speaker; they describe the noun biografija.

That is an important point for English speakers. In Serbian, adjectives and possessives agree with the grammatical gender of the noun, not with the biological sex of the person speaking.

So a man can say:

• Moja radna biografija je spremna.

And a woman can also say:

• Moja radna biografija je spremna.

The forms are feminine because biografija is feminine, not because the speaker is female.