Questions & Answers about Ne vidim crn kaput.
Why are crn and kaput in the accusative case here?
They are the direct object of the sentence. The verb vidim (I see) is doing the action to the black coat, which puts the phrase crn kaput into the accusative case.
If kaput is in the accusative case, why didn't its ending change?
Kaput is a masculine noun. In Croatian, when a masculine noun represents a non-living thing (it is inanimate), its accusative form looks exactly the same as its basic dictionary form.
Why doesn't the adjective crn have an accusative ending like -og here?
Adjectives must copy the grammatical rules of the noun they describe. Because kaput is a non-living masculine noun, its adjective also uses the non-living form, which has no extra ending. You would only use crnog if the noun was a living thing, like a black dog (crnog psa).
Where is the word for "I" in Ne vidim?
Croatian verbs change their endings to show who is doing the action. The -m at the end of vidim already means "I see." You don't need to add the word ja (I) unless you really want to emphasize it.