Phrasal Verbs Using 'On' & 'Upon' - Striving, Risking, or Revealing (On)

to direct one's attention, energy, or efforts toward a particular goal, task, or objective

to provide information to law enforcement or authorities about someone's actions, particularly illegal or unethical actions

to demand something firmly and persistently

to reveal information that was meant to be kept a secret

to give away information one has obtained about someone, particularly to someone in authority

to watch an event or incident without getting involved

to secretly observe someone or something with the intention of gathering confidential or hidden information

to focus one's effort, time, or attention on something in order to achieve a particular goal