A central theme of Margaret Atwood's "Spelling" (1981) is the power of words. This theme is explicitly stated with the line "A word after a word/ after a word is power." It is also explored more deeply throughout the poem as the narrator considers different types of power.
The power of being able to write or "spell" is explored at the beginning and end of the poem through the daughter learning to spell with plastic letters. This is also relevant in the second section of the poem as the narrator wonders about women who chose not to have children in order to "mainline words." Later a witch character is introduced whose power is in her voice. Her executioners prevent her from speaking to take away her power. This also suggests the idea of magical or occult power.
Witchcraft and writing are both presented as types of power connected with words. For the narrator of "Spelling" the power of words is particularly potent for women, who often have this power taken away.