check up on somebody/something phrasal verb (see also check)

1. to try to find out if someone is doing what they said they would do or what you want them to do:
Don’t worry; no one is going to check up on you.

2. to make sure that something is true or correct:
Dustin called me to check up on some facts.

[TahlilGaran] Dictionary of Contemporary English ▲

check up on
check up on (someone)
to try to discover what someone is doing, esp. secretly.
I think he stops by my office to check up on me, to make sure I'm actually working.

[TahlilGaran] English Idioms Dictionary ▲