What is another word for are onto someone?
Pronunciation: [ɑːɹ ˌɒntʊ sˈʌmwɒn] (IPA) 
The phrase "are onto someone" means that a person has figured out someone else's motives or plans. Some synonyms for this phrase include "have seen through," "have discovered," "have uncovered," "have detected," "have deciphered," "have divined," and "have deduced." These words all convey the idea that the person in question has been exposed or uncovered in some way. They suggest that the truth has been revealed, and there is nowhere to hide. When someone is onto you, it can be a stressful experience, but it can also be an opportunity to be honest and transparent.
