Final answer:
In 'The Giver,' although Jonas's mother does not give a specific warning, the story suggests that turning twelve will bring major changes with new societal roles and responsibilities for Jonas.
Step-by-step explanation:
In Lois Lowry's The Giver, Jonas's mother doesn't give a specific warning about how his life will change after he turns twelve, as the text provided does not directly relate to this event. However, in the context of the novel, it is implied that life will bring significant changes and responsibilities that come with becoming a designated member of society with a specific role. Jonas's community in The Giver adheres to a strict system of assigning roles to children once they reach the age of twelve during the annual Ceremony of Twelve, and these roles determine their futures within the community.