Alphonso is Celie and Nettie’s stepfather who takes over the responsibility of raising them after their mother dies. The girls are unaware that he is not their biological father until many years later. Their belief that Alphonso is their real father causes them severe emotional trauma, because Alphonso sexually abuses both of his stepdaughters. He begins to rape Celie when her mother falls ill and is no longer physically able to have sex with him. After multiple rapes, Celie becomes pregnant with Alphonso’s child. When she gives birth, he takes the baby from her immediately. Celie assumes that he’s killed the child, but it’s later revealed that he gave the baby—as well as the second child Celie has by Alphonso—to Samuel and Corrine. Not long after the birth of the first child, Celie’s mother dies, leaving her and Nettie in Alphonso's full control with no one to protect them from his abuse.

After Celie’s pregnancy, Alphonso grows tired of Celie and begins to take an interest in Nettie, but Celie keeps him from abusing Nettie by actively encouraging him to rape her instead. When Mr. ______ begins inquiring about taking Nettie for a wife, Alphonso convinces him to take Celie instead, claiming that Celie, who is less beautiful and less educated than Nettie, will make a more servile and hardworking wife. Alphonso’s insistence on selling Celie to Mr. ______ implies that he wants Celie out of the family so that he is free to rape Nettie instead.

Alphonso treats women as sexual objects and servants. He does not show any of the women in his life humane treatment. Although almost all the male characters in The Color Purple behave in misogynistic ways, ranging from expecting submission from women to physically and emotionally abusing women, Alphonso’s hatred of women is particularly heinous. He is almost entirely to blame for Celie’s difficult life circumstances. If he hadn’t raped and impregnated her when she was a child, she wouldn’t have needed to drop out of school, which severely limited her opportunities in life. He traumatized Celie and kept her from receiving an education, one of the few things that truly makes a difference in the lives of the disenfranchised people in the novel. Additionally, while Harpo and Mr. ______ both reflect on their misogyny and make some positive changes to their behavior over time, Alphonso does not. The only thing Celie ever receives from him is the rights to the house he inherited after her mother’s death.