"Daddy" is perhaps one of Sylvia Plath's best known works. It was written shortly before her death, and published posthumously in Ariel in 1965. "Daddy" can be seen as a response to Plath's complex relationship with her father, Otto Plath, who died shortly before her eighth birthday as a result of undiagnosed Diabetes Mellitus. As a result of her father's death, the voice of the poem, not to be confused with Plath, developed an Electra complex. The poem "Daddy" deals with her deep attachment to the memory of her father, and the unhappiness it caused in her life. "Daddy" can also be seen as an attempt by Plath to deal with her mixed feelings at her father's death. She does this through reinventing her father as a Nazi, and herself as a Jew, creating an 'oppressor-oppressed' relationship.
Perhaps the first thing one notices about "Daddy" is its nursery-rhyme-like quality. Plath begins using this device on the first line of the poem, with
"You do not do, you do not do
Any more, black shoe
In which I have lived like a foot
For thirty years,"
She continues to establish this almost childish quality throughout the poem, in the first stanza calling to mind the nursery rhyme There was an Old Woman Who Lived in a Shoe. She continues this throughout the poem, for example using 'Achoo' instead of 'sneeze', 'chuffing' to describe the noises made by a train, or the use of the word 'gobbledygoo' to describe things generally attributed to Nazis. These rather innocent, childlike phrases and images in the poem are juxtaposed with the dark, rather disturbing subject matter; images of concentration camps, nazis, vampires, and devils.