fill in on
phr. v..phr. v.. to give someone the details or information they missed about a situation.
phr. v.. to provide a person with missing information or updates regarding a specific topic or event.
Can you fill me in on what happened at the meeting?
Since I was on holiday last week, my manager spent an hour filling me in on the new project.
The legal team spent the afternoon filling the board in on the potential ramifications of the recent court ruling.
requires a person as the direct object and the topic as the prepositional object.
contrast with 'fill in' (to complete a form) to show how the preposition 'on' changes the meaning to information sharing.
I will fill in you on the news.I will fill you in on the news.the person being informed must come between 'fill' and 'in' because this phrasal verb is separable.