Sentence 1: Shane likes to read books, to go to movies, and to take his dogs on long walks.
Parallel structure (or parallelism) means using the same pattern or words to help give equal levels of importance to multiple ideas in a sentence. In the case of Shane’s sentences, all of the verbs are in the infinitive in sentence 1, but change forms inconsistently in sentence 2, which destroys any chance for parallelism.