Take another look at the sentence:

Carlos not only missed his one-year anniversary with Adrianna __________.

The blank needs a simple past tense verb to follow but also. You chose but he also forgot his mother's birthday, which is an entire main clause and thus causes a parallelism error.

Before you continue, review the rules for parallel structure.

Go back to the sentence to try again.

HomeTermsExercises MOOCHandoutsPresentationsVideosRulesAboutShopFeedback