Remember in the beginners’ lessons where we termed the Major Chords 1,4 & 5 as Primary Chords in any given key.
Secondary Chords are basically minor chords on the 2nd, 3rd and 6th degree of the Diatonic scale (Major Scale)
In the key of C Major, the secondary chords are 2,3 and 6 of the C Major Scale.
D minor triad (DFA) = 2 chord or simply II
E minor Triad (EGB) = 3 chord or simply III
A minor triad (ACE) = 6 Chord or simply VI
In Key F, the secondary chords are the 2,3 & 6 of the F Major Scale.
G minor triad (GBbD) = 2 chord or simply II
A minor triad (ACE) = 3 chord or simply III
D minor triad (DFA) = 6 Chord or simply VI
Can you attempt to get the Secondary Chords in the Key of G?