keep track

keep track (third-person singular simple present keeps track, present participle keeping track, simple past and past participle kept track)

1. To monitor; to track or record; to understand or follow.

   Please sign in, so that we can keep track of who is here.

• Used with or without "of":
  • There are many versions, and it's difficult to keep track.
  • There are many versions, and it's difficult to keep track of them all.

• keep tabs on