Major: half steps between scale degrees 3 and 4; 7 and 8
Harmonic minor: half steps between scale degrees 2 and 3; 5 and 6; 7 and 8
Natural minor: half steps between scale degrees 2 and 3; 5 and 6
Assending melodic minor: half steps between scale degrees 2 and 3; 7 and 8