nagoveštavati

1. (of signs, events) to herald; to foreshadow; to signal
   Tamni oblaci nagoveštavaju oluju. — Dark clouds herald a storm.
   Sve nagoveštava da će cene opet rasti. — Everything suggests that prices will rise again.
2. (of a person) to hint; to suggest
   Ministar nagoveštava da će uskoro podneti ostavku. — The minister is hinting that he will resign soon.

Often followed by a clause: nagoveštavati da…; the perfective is nagovestiti.