The third of the V chord is lowered, creating a minor V chord, which softens the dominant function and creates a more modal sound in the progression.

The third of the V chord is raised, creating a major V chord, which provides a stronger pull towards the tonic and establishes a clearer sense of tonality.

The fifth of the V chord is lowered, creating a diminished V chord, which increases tension and creates a more ambiguous resolution to the tonic.

The root of the V chord is raised, creating an augmented V chord, which enhances the chromatic movement in the bass line and adds color to the progression.