Hi there,

I would like to know the exact meaning of the expression 'be onto somebody' in the following context:

'John knows Tony, and he's onto Tony, and Tony's honest with him.

I tried to look it up almost everywhere, but with no result.

Thanx in advance, Emotion: smile

To 'be on to someone'

To understand someone and their hidden motivations.

Child in kitchen being suspiciously quiet, mother looks in suspecting mischief and finding child with suspicious 'butter wouldn't melt' expression: 'I'm on to you. What have you been doing?!'
A guess from a non-english speaker

I'd like to explain with an example--"It means when the two are discussing when to go for a holiday, the final date is always the one that is firstly proposed by John".
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I see. Well, yes, sounds good, thank you.

Can anyone confirm that? Emotion: smile
 nona the brit's reply was promoted to an answer.
Thank you very much, nona.

Your explanation has helped me la lot!

Have a nice day,

Students: We have free audio pronunciation exercises.

To be onto something or someone is to be aware of information related to it or them, esp. when they are trying to deceive you:
Everybody is onto your game -- why don't you admit you lied?

It's from cambridge online dictionary:)



To be onto someone means to understand what their up to or what they're doing
If someone is trying to deceive you and "you are onto them" it means that you see through their shenanigans and you can't be fooled.
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