Shakespeare uses many motifs to expand on the themes of the story. His most-used motif revolves around filial responsibility. Each of the two plots contains characters who betray their fathers. Goneril and Regan flatter their father, King Lear, and then betray him. The drastic change that occurred in their attidtude towards their father is clearly evident through Goneril's speech before:
'Sir, I love you more than words can wield the matter;
Dearer than eye-sight, space, and liberty;
Beyond what can be valued, rich or rare;
No less than life, with grace, health, beauty, honour;
As much as child e'er loved, or father found;
A love that makes breath poor, and speech unable;
Beyond all manner of so much I love you.' (Act I, Sc i, Ln 57-63)
and after she had been allotted one half of the kingdom:
''Tis his own blame; hath put himself from rest,
And must needs taste his folly.'
(Act II, Sc ii, Ln 289-290)
They both were interested only in getting Lear's land, and used any means necessary to get it. Edmund, in the other plot of the play, deceives his father in order to gain his favor. Edmund, the Earl of Gloucester's bastard son, tells his father that Edgar, Gloucester's legitimate son, is plotting to ruin Gloucester. This causes the Earl to banish Edgar and give his title and land to Edmund.
The ironic misuse of power used by the Earl of Gloucester shows up in both plots. Gloucester punishes Edgar and later finds that Edmund was the one taking advantage of him. Similarly, Regan and Goneril gain Lear's favor, while Cordelia is left 'dowerless' and banished from the kingdom. In the end, though, Cordelia saves Lear from the betrayal of Goneril and Regan.
Shakespeare develops these major motifs with supporting motifs.