1
general::
Phrase(s): *onto something
1. Fig. alerted to or aware of a deceitful plan. (*Typically: be ~; catch ~.) • The cops are onto your little game here. Fig. having found something useful or promising; on the verge of discovering something. (*Typically: be ~; get ~.) • I think we are really onto something this time. • I am onto a new discovery., Phrase(s): *onto someone
seeing through someone’s deception. (*Typically: be ~; get ~; catch ~.) • By the time we got on to the con artists, they were out of town. • The sheriff got on to Jed, and Jed wanted to get out of town fast.
McGrawhill's American Idioms And Phrasal Verbs