" To check up on someone" means to watch someone, to monitor their behavior, to look to see what they're doing, usually to find out if they're doing something wrong – if they're doing something they should not be doing.

“检查某人” 的意思是观察某人， 监视他们的行为， 看看他们在做什么，通常是为了查明他们是否做错了什么——如果他们在做不应该做的事情.