Another skill in memory retention is the sound of primary chords, and their arpeggios, in all major keys. In the Key of G that would be the G chord, the C chord, the D7 chord, and back to the G chord.
The above chords are based on the scale degrees I (Tonic), IV(Sub Dominant), V7(Dominant), and back to I(Tonic).
I(G major chord)= Tonic = G, B, D = syllables in solfeggio moveable do system = do, me, sol. Now add one more of the sounds, with in the pattern, to complete a pattern in your tonal memory = do, me, sol, me, do = G, B, D, B, G. Sound wise listen to the diagram below for the chord and then the arpeggio.
It is the arpeggio that we want to learn to sing from syllable memory. "do, me, sol, me, do". This pattern is done on each of the main chords in every musical key.
In singing the syllables .. sol is sometimes pronounced simply as "so" but written as "sol". Your learning a bit of solfeggio at this point, a very important part of sight singing by musicians that look at the music and then "think sound".
It is one thing to have been raised around musicians and people that sing, but if that was not emphasized in your family as young person, then you have a lot more work cut out for you to learn as you are in a slight disadvantaged position, as I was.