parallelism in a series : Common Errors in English

About parallelism in a series

Phrases in a series separated by commas or conjunctions must all havethe same grammatical form. “They loved mountain-climbing, to gather wild mushrooms, and first aid practice” should be corrected to something like this: “They loved to climb mountains, gather wild mushrooms, and practice first aid” (all three verbs are dependent on that initial “to”). Fear of being repetitious often leads writers into awkward inconsistencies when creating such series.
Lightning fast vocabulary building for SAT, ACT, GRE, GMAT and CAT