Meaning of the word "be on someone's back" in English

What does "be on someone's back" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

be on someone's back

US /bi ɑn ˈsʌm.wʌnz bæk/
UK /bi ɒn ˈsʌm.wʌnz bæk/
"be on someone's back" picture

Idiom

to constantly criticize or nag someone

Example:
My boss is always on my back about deadlines.
She hates it when her parents are on her back about her grades.