The circular nature of the themes in this story is common in literature. It is an example of “the sins of the father” being visited upon the son. Okonkwo is so determined not to be like his own father, considered weak and worthless by the Ibo tribe, that he lets this goal cloud his reasoning. He becomes a controlling, angry and irrational man. He makes decisions based on his obsessive desire not to appear weak. These decisions are often compulsive and irrational and have long-range negative consequences for him. He commits three murders in the novel (Ikemefuna, Ezeudu’s son, and a government official ). He also beats his wives and shoots at them when they fail to prepare his dinner. These actions cause things in his life to “fall apart.” Okonkwo’s father was considered weak and unable to support his family, but beloved and easy-going. In trying not to be like him, Okonkwo goes too far the other way, in one of the novels’ great ironies.
Ikemefuna is sent to live with Okonkwo’s tribe as a peace offering for the killing of an Ibo girl. He lives with Okonkwo for three years and Okonkwo comes to love him and appreciate him more than his own son, Nwoye because Ikemefuna has qualities and talents that Okonkwo admires, qualities lacking in his own son. The Ibo tribe later kills Ikemefuna because the Oracle of the Hills and the Caves have told them to do so. Okonkwo, however, is warned by a tribal elder, Ezeudu, not to take part in the killing as it would have dire consequences for him. While they are walking in the woods, however, Okonkwo does participate in the killing of Ikemefuna because he does not want to appear weak in front of the other men. As predicted, Ikemefuna’s death and Okonkwo’s bad decision to participate in it cause things to “fall apart” in Okonkwo’s life. Ikemefuna and Nwoye had become good friends, brothers in spirit if not blood, and the sensitive Nwoye becomes alienated from his father over Ikemefuna's death. To use a cliche, “what goes around, comes around” (regarding the circular events in the story). Nwoye later leaves the tribe and becomes a Christian, rejecting the beliefs of a father he perceives as harsh and unloving.
Okonkwo favors his daughter Ezinma, who is his wife Ekwefi’s only child. Ekwefi has lost many other children. Ezinma is not only beautiful, but she is the only one of Okonkwo’s children that is totally like him. They have a very close relationship and Ezinma is allowed to do things that the other children are not. This is unusual because she is a girl, yet Okonkwo treats her as if she were a son. Because of his favored treatment of Ezinma, however, Okonkwo’s other children are alienated from him, including Nwoye. Once again, Okonkwo’s decisions return in circular fashion to haunt him because Nwoye leaves the tribe to join those that are aligned against Okonkwo.
Basically what the question is asking for is how Chinua Achebe uses the circular timeline (basically foreshadowing) to tell a story. the last 2 sentences of the second paragraph on page 27 (beginning of chapter 4) states that "But no one thought it would last three years. They seemed to forget all about him as they had taken the decision." This immediatly tells you that Ikmefuna only stays with Okonkwo for 3 years and that eventually a "decision" is made ending the 3 years that he stays at with Okonkwo. This circular timeline comes full circle when Ikmefuna is killed by Okonkwo 3 years later. This ocours again in Ezinmas story of how she almost died.