Symbol: Elevator
The Elevator is a symbol of movement and potential. It is how Wonka navigates his factory and how Charlie now experiences his factory and the majestic (but frightening!) world of outer space. As an elevator does, it literally moves him, but it also figuratively transports him out of his humdrum existence into one of excitement and delight.
Symbol: Candy
Candy is a potent force for children (and some adults). In its sweetness and decadence, it represents something sometimes unattainable, something immensely desirable. The candy in the Wonka books symbolizes desire as well as prosperity, for Charlie owns everything within the Factory walls. It also symbolizes youth to an extent--and, since Charlie will now run the Factory as Wonka did, it is as if he had attained perpetual youth.
Symbol: Bed
A bed is a place of rest and repose but it is also one that represents decay, indolence, and even death. The fact that the three grandparents are purposefully bedridden for the duration of the novel symbolizes their extreme old age and lack of dynamism and ability. It is telling that the first time they decide to get out of bed, they become young (too young, of course, since they take Wonka-Vite).
Motif: Nonsense
Nonsense words and songs permeate the text, and they primarily derive from Wonka. He uses them to confuse, to obfuscate, to mock. Though he is an adult, he deliberately uses the meaningless prattle of children to vex his listeners. The irony is that they often take him seriously, allowing Dahl to indicate that he thinks a lot of adults do not understand children and completely miss the intent of their words.
Motif: Song
Wonka sings his nonsense song and the Oompa-Loompas sing songs repeatedly throughout the text. This motif acts as a transition from one scene to another, as well as a way for a moral or a message to be passed down. The most blatant use of this is the story of Goldie Pinklesweet, used to warn the old ones and foreshadow their imminent disaster with Wonka-Vite. The songs seem lighthearted--especially as they are delivered by funny orange and green creatures--but they are often dark and foreboding.