This is the 2nd most frequent Croatian word.
u
"In."
In this sentence, 'u' is a preposition indicating location within a confined or defined spatial area, translated as 'in'.
U kutiji se nalazi nekoliko čokolada.
There are several chocolates in the box.
Here, 'u' is a preposition indicating direction or destination, commonly translated as 'to' in English.
Idem u grad kako bih kupio knjige.
I am going to the city to buy books.
Here, 'u' is used as a preposition indicating a point in time, equivalent to 'on' or 'at' in English.