keep a close watch on

keep (a) close watch on (someone or something)

To monitor someone or something closely. Keep a close watch on this pot so that the soup doesn't boil over. I've asked the manager to keep close watch on Tom. I'm pretty sure he's been stealing from the register.
See also: close, keep, on, watch
Farlex Dictionary of Idioms.

keep a close watch on someone or something

to watch someone or something very carefully. Let's keep a close watch on Fred and his friends. I want to keep a close watch on the house across the street.
See also: close, keep, on, watch
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

keep a close ˈeye/ˈwatch on somebody/something

watch somebody/something carefully: Over the next few months we will keep a close eye on sales.
See also: close, eye, keep, on, somebody, something, watch
Farlex Partner Idioms Dictionary
See also:
  • keep a close eye/watch on somebody/something
  • keep watch on
  • keep (a) close watch on (someone or something)
  • keep a close eye on (someone or something)
  • close at hand
  • come close
  • play one's cards close to one's chest, to
  • close out
  • close by
  • sail close to (near) the wind, to