to focus on

https://tts.langeek.co/read?text=dG8gZm9jdXMgb24&hash=7101b4b2b658df8052ee09d79f2efb3e60f61791&lang=en&cache-only=0&driver=googletts

to inform on

https://tts.langeek.co/read?text=dG8gaW5mb3JtIG9u&hash=8656e99d26f9a9404348d7f44e82ec1456ab2067&lang=en&cache-only=0&driver=googletts

to insist on

https://tts.langeek.co/read?text=dG8gaW5zaXN0IG9u&hash=6241c02b09245565ea365a3804d7121c142816ac&lang=en&cache-only=0&driver=googletts

to let on

https://tts.langeek.co/read?text=dG8gbGV0IG9u&hash=42ade3898106d3e7305c91526e6796d13786f25f&lang=en&cache-only=0&driver=googletts

The idiom "tell on" is derived from the literal meaning of the words. To "tell on" someone means to report their actions or misdeeds to an authority figure or someone in a position of control or responsibility. Its origin is likely rooted in the natural human tendency to inform others about wrongdoing or suspicious behavior, particularly when it affects one's well-being or interests. It is frequently used in the context of children reporting on their peers or siblings, but it can apply to people of all ages.

What is the origin of the idiom "tell on" and when to use it?

to tell on

https://tts.langeek.co/read?text=dG8gdGVsbCBvbg&hash=034a750ca1a3d42711b60d48aff1eba793dc0b4d&lang=en&cache-only=0&driver=googletts

to look on

https://tts.langeek.co/read?text=dG8gbG9vayBvbg&hash=e7c6b19958b5e1ba41d4049fa6d99abd5bf89cb6&lang=en&cache-only=0&driver=googletts

to spy on

https://tts.langeek.co/read?text=dG8gc3B5IG9u&hash=953a52643183b4d54eacab87fdcea9b62785c997&lang=en&cache-only=0&driver=googletts

to work on

https://tts.langeek.co/read?text=dG8gd29yayBvbg&hash=1cfcb901c361b146c05a3b4f12cc4bb14f22352b&lang=en&cache-only=0&driver=googletts

Esforçando-se, arriscando ou revelando (sobre)

Striving, Risking, or Revealing (On)