on to

alternative onto

1. Upon; on top of.

   My cat just jumped on to the keyboard.

2. informalAware of.

   The thought-police were on to my plans of world domination.

   1 more example

   Fortunately “the F.B.I. was on to them” and foiled the plot, but the alleged kidnapping conspiracy, Walter argues, is a harbinger of worse to come.

   2022 January 12, Ross Douthat, “Let’s Not Invent a Civil War”, in The New York Times, →ISSN

3. Used to indicate, or signpost, logical progression to a new topic in a talk or discourse.

   Let's go on to item 3 in the list.

   1 more example

   Now. On to the system of active water uptake.