To give someone a heads up
(figurative) /ˈhedz.ʌp/ meaning to inform someone about something important. Literally, people must lift their heads up from their works to listen.
Example 1: I just want to give you a heads up that the customer will visit our office tomorrow.
Example 2:Just a heads up about tomorrow meeting will start at 10 AM.
To give someone the lowdown
/ˈləʊ.daʊn/ The most important facts and information about something
Example 1: I don’t have time to listen all the details. Please give me the lowdown.
Example 2: Give me the lowdown on the new project.
To fill someone in
/fɪl/ to tell someone about something, especially something happened when they were not there
Example: I didn’t join the conference yesterday. Could you please fill me in?
to do someone’s job temporarily
Example: John is sick today. So I fill in for him at the conference.
To drop someone a line
UK /drɒp/ US /drɑːp/ To write a letter for someone, especially a short informal one.
Example: please drop me a line with the prices.
Example 2: I’ll drop you a line to confirm the details
To keep someone updated/posted
To regularly tell someone what happening in an important situation.
Example: the boss is waiting for the feedback from the customer. So he tells his secretary to update him information regularly by saying “Please keep me posted/updated”
To keep someone in the loop
to regularly inform someone about something. (similar to keep someone updated)
Example: you are the PM of the project but please keep me in the loop.
To get back to someone
to reply to someone. Or to talk again in order to give some information that were not able to talk previously
Example: has the customer got back to us?