keep tabs on someone/something

keep tabs on someone/something

COMMON If you keep tabs on someone or something, you make sure that you know what they are doing or what is happening to them, often in order to control them. We know that somebody was keeping tabs on her. It's their job to keep tabs on the financial situation. Note: Originally, this was an American expression which uses an American sense of `tab', meaning an account or bill, which can be used to keep a record of what someone spends.
See also: keep, on, something, tab