let on — reveal a secret (often used in the negative: not let on)
to allow other people to know something that is secret or private, often by accident or by not hiding it well; to admit or reveal information that you were supposed to keep hidden.
Say it like a native
Textbook She gave no indication that she was aware of the plan.
Native She didn't let on that she knew.
'Let on' naturally means reveal you know something (usually in the negative). 'Gave no indication' is formal.
Pattern: let on (about sth) | let on (that...)
In use
- She didn't let on that she already knew about the surprise party.communication
- In my opinion, it's important not to let on if you know a friend's secret, because trust is essential in any relationship.IELTS speaking
Common mistake
✗ Don't let on him about the party.
✓ Don't let on (to him) about the party.
'Let on (to someone) ABOUT/THAT' — don't put the person straight after 'let on'.
Common collocations
let on— didn't let on, never let on, that she knew, about it
Don't confuse it
This sense is different from the literal meaning of 'let' (to allow) and does not mean to permit someone to do something. Instead, it is about revealing information, often unintentionally or subtly.