What you're training
Most progressions telegraph their ending long before the last chord lands — the real skill is hearing which kind of ending actually arrives. An authentic cadence resolves the dominant, V, straight down to I: the strongest close in tonal music. A plagal cadence skips the dominant entirely and resolves IV to I instead — the gentler "amen" close. Training your ear to tell them apart means listening to how the last chord gets there, not just where it lands.
Two levels, one skill
Level 1 stays in C major and asks the everyday question: authentic or plagal? Level 2 moves to A minor and raises the stakes — the progression can close on a plain minor close (i), the expected dark ending, or unexpectedly brighten into a Picardy third, where the final chord turns major (I) instead. Same minor-key setup, one very different last chord.
Go deeper
How real pieces end — the census, including a genuine Picardy → traces exactly how often composers reach for each kind of ending, Picardy included. The theory: cadences → covers how phrases end and why authentic, plagal, and Picardy all still count as one. The ending that breaks the pattern entirely → is the other lane of this series — instead of choosing which real ending you get, the dominant just doesn't resolve where you expect at all.
Where it fits
Comfortable with chord quality and cadence resolution already? Final cadences is the next layer — the exact V-to-home and IV-to-home pulls you already hear, now compared against each other and against the one ending that flips the whole mood. The full drill ladder has everything else.