Three years.
Ikemefuna is the boy that is sent to live with Okonkwo. Eventually the boy becomes much like Okonkwo's own son, and Ikemefuna even calls Okonkwo father.
Okonkwo becomes a father to Ikemefuna, and Ikemefuna calls Okonkwo father. Ikemefuna is like the second man in the house, the closest to Okonkwo's personality, and helps to develop Nwoye's manhood. Okonkwo likes Ikemefuna, but does not show his feelings towards Ikemefuna because to do so would be unmanly.
Ikemefuna is led by the tribe on a long march outside of its lands. One tribeman cuts him with a machete. As Ikemefuna runs to Okonkwo for safety, Okonkwo chops Ikemefuna down with his machete.
Okonkwo is part of the group which leads Ikemefuna out of the village to be killed. After Ikemefuna receives the first blow and runs towards Okonkwo for protection, Okonkwo strikes Ikemefuna down, not wanting to be seen as weak.
Mbaino is the village which Ikemefuna lives in before he is forced to live with Okonkwo in Umuofia in order to repent his father's crime. It is significant because in essence, things begin to "fall apart" for Okonkwo after Ikemefuna is killed by Umuofia. Okonkwo becomes haunted by his choice to kill Ikemefuna. In fact, Ikemefuna's death begins Okonkwo's downfall.
Ikemefuna spends 3 years away from his biological family and with Okonkwo's family.
The village elders told Okonkwo to take care of Ikemefuna until his fate was decided. When Ikemefuna is sentenced to die, Okonkwo is afraid of being seen as weak. When Ikemefuna cries to him, Okonkwo takes care of Ikemefuna, (kills him).
Ikemefuna is taken from his village as part of a settlement for the death of a Umuofian woman in the marketplace of his village. He goes to live with Okonkwo. Later, Ikemefuna is sentenced to die, but he does not know it.
Ikemefuna is taken into Okonkwo's home as part of the compensation for a murder committed by the neighboring village. He lives with Okonkwo's family and forms a close bond with Okonkwo's son, Nwoye. However, tragically, Okonkwo ultimately participates in Ikemefuna's killing to demonstrate his masculinity and avoid appearing weak.
Okonkwo struck the last blow to Ikemefuna because he did not want to seem weak or cowardly, even though Okonkwo likes Ikemefuna, and thinks of him as his adopted son.
Okonkwo tells Ikemefuna that he is to be taken home. If you do not consider 'home' to be Ikemefuna's final resting place, then this is indeed a lie.
Ikemefuna was the boy who was adopted by Okonkwo in Chinua Achebe's novel Things Fall Apart. He was taken in by Okonkwo's family as part of a peace settlement between their village and a neighboring one.