keep tabs on somebody/something
keep tabs on
Observe carefully, keep a record of. For example, I hate having my boss keep tabs on my every move, or We've got to keep tabs on outgoing mail so we can keep track of postage. This expression uses to tab in the sense of "an account." [Late 1800s] Also see keep track.
keep tabs (or a tab) onmonitor the activities or development of; keep under close observation. informal
1978 Mario Puzo Fools Die Jordan knew that Merlyn the Kid kept tabs on everything he did.
keep (close) ˈtabs on somebody/something(informal) watch somebody/something very carefully; keep informed about somebody/something: I’m not sure about Johnson — we’d better keep tabs on him until we know we can trust him. ♢ I’m keeping tabs on the number of private phone calls you all make from the office.
keep tabs onInformal
To observe carefully over time: Let's keep tabs on expenditures.