Final answer:
A shift in a text's structure may occur due to changes in transitional elements, verb tense consistency, or variety in sentence structures. Such shifts can be intentional, aiding in effective rhetorical delivery.
Step-by-step explanation:
Typically, in terms of structure, a shift in a text is created by a change in the use of transitional words and phrases, verb tense consistency, or sentence structures. For example, transitioning from one tense to another without proper signalling can jar the reader, and hence, indicates a shift. Similarly, a sudden change from complex to simple sentences, or the introduction of a new topic through transitional phrases, also signifies a shift. These shifts are often deliberate, with the writer's intent to either meet or challenge traditional expectations. When such changes are executed in rhetorically effective ways, they contribute to the dynamic quality of the text, guiding the reader through the progression of ideas or signaling changes in tone or focus.