The words sole and soul are homophones: they sound alike but have different meanings.
DEFINITIONS
The noun sole refers to the underside of a foot or shoe or to a kind of flatfish. The adjective sole means single, solitary, or the only one.
The noun soul refers to spirit, a vital principle, the spiritual nature of humans.
EXAMPLES
Social Security is the sole source of income for many senior citizens.
For decades the Japanese fished for sole off the coast of Alaska.
“True sympathy is the personal concern which demands the giving of one’s soul.”
(Martin Luther King, Jr.)
“I go on these teams Hospice sends around. Even at the very end, there’s something in there, a soul or whatever, you have to love.”
(John Updike, Rabbit Remembered. Knopf, 2000)