Breakdown of Osjećam velik unutarnji mir u sebi.
velik
big
u
in, into
sebe
oneself (stressed reflexive)
mir
peace (m)
Questions & Answers about Osjećam velik unutarnji mir u sebi.
Why do we use sebi here instead of meni (within me)?
Because the subject of the sentence is 'I' (implied by osjećam) and the location refers back to that same subject. In Croatian, whenever the action refers back to the subject, you must use the reflexive pronoun sebe (oneself) rather than a regular personal pronoun. Here, it is in the locative case, sebi.
The current lesson teaches that the locative of sebe is sebi, but the accusative is sebe. Why does the preposition u trigger the locative here?
The preposition u can take either the locative or the accusative case depending on the context. You use the locative case (u sebi) when describing a static location, like where a feeling resides. If you were describing motion or direction towards something, u would take the accusative case (u sebe).
Mir is the direct object, so why don't velik and unutarnji take accusative endings like -og, and why does velik drop its final -i?
Mir (peace) is a masculine inanimate noun, so its accusative form looks exactly like its nominative form. The adjectives follow suit. Also, velik is in its indefinite form (meaning 'a great peace' rather than 'the great peace'), which is why it doesn't have the final -i that you see in the definite form veliki.