Play all 7 triads in C major, root position, ascending — say the roman numeral out loud for each.
Do the same thing in one other key from the cheat sheet.
Loop I – V – vi – IV in two different keys.
In a major key, swap the IV chord for iv (make it minor) and just listen to what that does to the mood. That’s a borrowed chord.
Pick a song you like. Try to figure out by ear which scale degree each chord is. If one chord doesn’t fit the table for that key, figure out which of the three reasons in the previous page explains it.