Your Rosetta Stone for this legerdemain is the term “digraph.” It refers to a two-letter designation that denotes some kind of status. A good example of a well-known digraph is CI, which means ...

We're gonna be learning about the C-H digraph that says ch, like chin, and the S-H digraph that says sh, like ship. Are you ready to read and write with me? - [Children] Yeah! - Great.