This sentence's error is that it uses an adverb in the place of an adjective. "Badly," as an adverb, is referencing not the quality of the dog's odor, but its poor ability to smell.

This sentence has three subjects: "Sarah," "Emilie," and "Jenn." Because of this, the sentence requires a form of the word "both" that is used to refer to groups of three or more. "Both" would be correct if only two of the girls were racing.  However, since all three are racing, we need to use the adverb "all" instead of "both." The corrected sentence would read "Sarah, Emilie, and Jenn competed against one another in the four hundred meter hurdle event, and they all scored similarly."

The word "original" is an adjective and should modify a noun. Here, it modifies the verb "passed". An adverb would be correct: "Many popular books and movies are inspired by folktales that were originally passed down orally from generation to generation."

The word "good" is an adjective and should describe a noun. Here, it describes the verb "went" and is grammatically incorrect. Changing "good" to the adverb "well" corrects the sentence's error. The corrected sentence reads, "Despite the terrible dress rehearsal the night before, the opening performance of Romeo and Juliet went really well."

This sentence uses an adjective (“complete”) to describe another adjective (“wrong”). An adverb is the correct part of speech in this context. The corrected sentence reads: "Tom had a terrible sense of direction but a wonderful sense of humor; he consistently headed off in the completely wrong direction but laughed about it later."

In this sentence, the adjective “painful” is used to describe the verb “dragged on.” As adjectives only describe nouns and pronouns, "painful" contains the sentence's error, and the adverb "painfully" would be a grammatically correct choice. The corrected sentence reads, "May dragged on painfully; Dorothy was counting the hours until graduation, and they couldn’t pass fast enough."

"Then" is an adverb that means at that particular moment, and "than" is an adverb used to compare two things, as in the sentence, "My fall coat is less heavy than my winter coat." So, "then" is being used incorrectly in this sentence and should be replaced with "than" in order to correct the sentence's error.

In this sentence, "uneven" is meant to modify the verb "baked." Therefore, an adverb is needed. However, "uneven" is an adjective. The adverbial form is "unevenly," so the correct sentence would read, "Because the oven did not heat properly, Megan's cupcakes baked unevenly; some were burnt and overdone, while others were still raw and runny." Remember that adjectives only modify nouns, and adverbs modify verbs, adjectives, or other adverbs.

In this sentence, the adjective “slow” is used to modify the verb “crept.” Adjectives should only modify nouns and pronouns, so to correct the sentence's error, the adjective "slow" should be replaced with the adverb “slowly." The corrected sentence reads, "The sloth crept slowly across the roadway, risking life and limb in his determination to explore the world on the other side."

In this sentence, the adjective “quick” describes the verb “remove.” An adverb would be more appropriate. The corrected sentence reads: Chad’s political views took an abrupt swing to the left, and he had to find a way to remove bumper stickers quickly.