This is the 6th most frequent Croatian word.
će
"Će" is a particle used to indicate the future tense (will/shall).
Here, 'će' is part of the question construction in the future tense, combined with 'hoće' and flipped in word order for the question form.
Hoće li ona ići s nama?
Will she go with us?
In this sentence, 'će' functions as an auxiliary verb to form the future tense with the verb 'doći' (to come).
On će doći kasnije.
He will come later.
In this example, 'će' again serves as an auxiliary verb indicating the future tense for the verb 'pomoći' (to help).