Prije ispita iz kemije ona je uzbuđena i malo nervozna.

Because the prepositions prije and iz both require the genitive case.

• ispit (exam) → genitive singular: ispita
• kemija (chemistry) → genitive singular: kemije

So:

• prije ispita = before the exam (literally: before (of) exam)
• iz kemije = of chemistry / in chemistry (literally: from chemistry)

In Croatian, many prepositions fix the case of the noun after them.
prije + genitive, iz + genitive is the standard rule.

Two reasons:

1. Articles don’t exist in Croatian.
   You never add something like the or a, so ispit can already mean an exam or the exam depending on context.

2. Case endings replace English prepositions + word order.
   You cannot leave ispit in the basic form after prije, because prije must be followed by the genitive:

   • ❌ prije ispit kemije
   • ✅ prije ispita iz kemije

kemije is also in the genitive because iz also takes the genitive:

• ispita iz kemije = exam of chemistry / chemistry exam

Yes, you can, and it’s correct:

• prije ispita iz kemije = before the exam in chemistry
• prije kemijskog ispita = before the chemistry exam

kemijskog is the genitive singular masculine form of the adjective kemijski (chemical, chemistry-related) agreeing with ispita (genitive of ispit).

Both are natural; ispita iz kemije is very common in everyday speech.
kemijskog ispita sounds a bit more compact, slightly more formal or written.

Because adjectives must agree in gender, number, and case with the noun they describe.

• ona = she → feminine singular
• So the adjectives must also be feminine singular:
  • uzbuđena (fem. sing.)
  • nervozna (fem. sing.)

nervozan is the masculine form, used for he:

• On je nervozan. = He is nervous.
• Ona je nervozna. = She is nervous.

malo here is an adverb modifying the adjective nervozna:

• malo nervozna = a little nervous / slightly nervous

So it softens the adjective, just like English a bit or a little.

Be careful not to confuse it with:

• mala (feminine adjective) = small, little (girl/female thing)
  • mala kuća = a small house
• malo can also be a pronoun/noun meaning a small amount / not much depending on context:
  • Imam malo vremena. = I have little time / not much time.

In this sentence it clearly functions as an adverb.

You can say:

• Ona je malo uzbuđena i nervozna.

but the meaning and nuance change slightly:

• ona je uzbuđena i malo nervozna
  → first emphasizes excited, then adds that she’s a little nervous.

• ona je malo uzbuđena i nervozna
  → suggests she is a bit excited and (fully) nervous.

So the position of malo mainly changes what it modifies:

• malo nervozna = slightly nervous
• malo uzbuđena = slightly excited

Croatian word order is flexible, but small shifts can change emphasis.

Grammatically, yes, Croatian often drops subject pronouns because the verb form shows who the subject is:

• Prije ispita iz kemije uzbuđena je i malo nervozna.
• Prije ispita iz kemije je uzbuđena i malo nervozna. (colloquial, see note below)

However:

1. Standard word order with clitic je
   In more careful/standard Croatian, the clitic verb je is usually in second position:

   • Ona je uzbuđena.
   • Prije ispita iz kemije ona je uzbuđena.
   • Prije ispita iz kemije uzbuđena je i malo nervozna.

2. Dropping ona
   Is very natural:

   • Prije ispita iz kemije uzbuđena je i malo nervozna. Usually the subject (she) is clear from context or from earlier sentences.

So yes, you can omit ona; just pay attention to where je is placed in more formal speech/writing.

je is a clitic (a short, unstressed form of the verb biti = to be), and Croatian clitics normally:

• go in second position in the clause.

So:

• Ona je uzbuđena. = She is excited.
  (je is the second element: ona → je → uzbuđena)

You can say uzbuđena je when:

• another phrase comes first, like:
  • Prije ispita iz kemije uzbuđena je i malo nervozna.
    • Prije ispita iz kemije (1st slot/phrase)
    • uzbuđena (2nd element)
    • je (clitic, jumps to second position in the clause) But ona uzbuđena je in isolation sounds unusual and non-standard.

In this sentence, they function as predicative adjectives describing a state:

• uzbuđena = excited
• nervozna = nervous

Historically, uzbuđena comes from the past passive participle of uzbuditi (to excite), but in everyday language it’s treated as an adjective: something you are, not something you do.

So:

• Ona je uzbuđena. = She is (in a state of being) excited.
• On je nervozan. = He is nervous.

You don’t need to think about participles here; just treat them as normal adjectives agreeing with ona.

Both can translate as before the exam, but there’s a nuance:

• prije ispita

  • very common, neutral
  • prije
    • genitive (ispita)
  • broadly “before (in time) the exam”

• pred ispitom

  • a bit more spatial/figurative, sometimes more formal
  • pred
    • instrumental (ispitom)
  • literally “in front of the exam”, but also used in a temporal sense

In many contexts they’re interchangeable, but:

• Prije ispita iz kemije ona je uzbuđena… sounds the most natural for describing her state before the exam in time.
• Pred ispitom iz kemije would also be understood and acceptable, just slightly different style.