What is another word for being onto someone?
Pronunciation: [bˌiːɪŋ ˌɒntʊ sˈʌmwɒn] (IPA) 
Being onto someone can mean a variety of things, including knowing their motives, suspecting their actions, or detecting their deception. To express this concept with different words, we could use synonyms like "being aware of someone's schemes," "having a hunch about someone's intentions," "sensing something fishy about someone," or "having an inkling that someone is up to no good." Other related phrases could be "having someone's number," "seeing through someone's facade," "knowing someone's game," or "keeping someone in check." These expressions all capture the idea of being vigilant, perceptive, and cautious when dealing with someone who may have ulterior motives.
