to focus on

https://tts.langeek.co/read?text=dG8gZm9jdXMgb24&hash=2eecd1467b51c69a008e8ab0f55a213c3298bedb&lang=en&cache-only=0&driver=googletts&accent=US

to inform on

https://tts.langeek.co/read?text=dG8gaW5mb3JtIG9u&hash=eb2637200d24c952e04b5d75bd12ba7a5eadb953&lang=en&cache-only=0&driver=googletts&accent=US

to insist on

https://tts.langeek.co/read?text=dG8gaW5zaXN0IG9u&hash=3c6503f113a98818aacf6ae7cb44a4adee4be07c&lang=en&cache-only=0&driver=googletts&accent=US

to let on

https://tts.langeek.co/read?text=dG8gbGV0IG9u&hash=0819e929919bdb0566ec7b9324fa4db399ac1b03&lang=en&cache-only=0&driver=googletts&accent=US

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=5e92e6e7a551efa76707138a9586d04d447714b6&lang=en&cache-only=0&driver=googletts&accent=US

to look on

https://tts.langeek.co/read?text=dG8gbG9vayBvbg&hash=e39c525ac9fa4fcda0cb7e40aba715d9624a41a1&lang=en&cache-only=0&driver=googletts&accent=US

to spy on

https://tts.langeek.co/read?text=dG8gc3B5IG9u&hash=83f9fc5ad73e54be81b6f3babf2c64c034c0ff48&lang=en&cache-only=0&driver=googletts&accent=US

to work on

https://tts.langeek.co/read?text=dG8gd29yayBvbg&hash=38687eb841c9365fce181c5a8d6c9366233c343d&lang=en&cache-only=0&driver=googletts&accent=US

S'efforcer, risquer ou révéler (sur)

Striving, Risking, or Revealing (On)