Learn Hardcore Croatian: Film je kratak.

je is the 3rd person singular present of biti (to be), meaning is/it is.
It’s a clitic, which means it tends to appear in the second position in the clause. In neutral order, that gives you Film je kratak.
You can front another element for emphasis and the clitic still stays second, e.g., Kratak je film (emphasis on short).

Why is it kratak and not kratko?

kratak is the masculine singular adjective form and agrees with film (a masculine noun).
kratko is neuter singular or an adverb meaning briefly/shortly. You’d use kratko with a neuter subject, e.g., Predavanje je kratko (The lecture is short), or as an adverb: Govori kratko (He speaks briefly).
Predicate adjectives must agree in gender and number with the subject.

When do I use kratak vs kratki?

Croatian has short and long forms of some adjectives. For this word:
- Short (indefinite) form: kratak. Default in predicate position: Film je kratak.
- Long (definite) form: kratki. Default before a noun (attributive): kratki film (a short film).
Using kratki predicatively (e.g., Film je kratki) is possible only in marked, literary, or emphatic style; in everyday speech it sounds odd. Stick with kratak after the verb and kratki before the noun.

How does adjective agreement work here?

How do I say the negative?

Use nije (the negative of je): Film nije kratak.
To emphasize the negation, you can front it: Nije film kratak (It’s not that the film is short…).

How do I turn it into a yes/no question?

Standard Croatian: Je li film kratak?
Colloquial contraction: Je l’ film kratak?
In Serbian/Bosnian you’ll often see Da li je film kratak?, but Je li is the preferred Croatian standard.
Short answers: Je. (Yes, it is.) / Nije. (No, it isn’t.)

Can I change the word order?

Neutral: Film je kratak.
Emphasis on the adjective: Kratak je film.
Don’t place je at the end: Film kratak je is ungrammatical. Clitics like je want the second position.
You can also topicalize the noun: Taj film je kratak (That film is short).

What happens in the past or future?

How do I say very/quite/too short?

Does kratak refer to duration or physical length? What about height?

kratak covers duration and length: a short film (duration), short rope (length), short hair (kratka kosa).
For a person’s height, use nizak (not kratak): On je nizak (He is short [in height]).

How do I say a short film as a category/genre?

kratki film is the general term for a short film.
In film jargon, you’ll also see kratkometražni film (short‑length film).
Predicatively you’d still use kratak: Film je kratak, but as a noun phrase you say kratki film.

What case is kratak in here, and how does it change in other cases?

In Film je kratak, both the subject and the predicate adjective are in the nominative.
Attributively, the adjective declines with the noun. Examples with film (masculine, inanimate):
- Accusative (object): Gledam kratki film.
- Genitive: Nema kratkog filma.
- Dative: Pristupam kratkom filmu.
- Instrumental: S kratkim filmom.
- Locative: O kratkom filmu.

Can I omit je like in some headline styles?

In standard sentences, no: you must include je.
In headlines, notes, or very colloquial clipped speech, you might see it dropped, but that’s not standard prose: e.g., headline style Film kratak.

How do I pronounce the sentence?

Film: [film] — clear L (not English dark L), short i, final m as in English.
je: [je] — like ye in yes.
kratak: roughly [kra-tak] — trilled or tapped r, both a as in father, unaspirated t and k. Typical stress is on the first syllable in casual teaching guides.

What are the comparative and superlative forms?

Comparative: kraći — Film je kraći (The film is shorter).
Superlative: najkraći — To je najkraći film (That is the shortest film).
They agree like regular adjectives: kraća/kraće/kraći etc. depending on gender/number.