When comparing only two different people or things, as happens in this sentence between "the twins," the appropriate adjective is "better." In this sentence, both instances of "best" should be changed to "better." Therefore, the correct answer choice is "the boy was the better athlete, while the girl was the better artist."

The use of the word "both" in the example sentence makes it clear that Carla only has TWO jobs; therefore, a comparative adverb ("better") must be used instead of a superlative adverb ("best"). Superlative adjectives and adverbs are used only when more than two items are being compared in a sentence. The correct version of the sentence reads, "Carla enjoys both her jobs, but overall she likes working at the book store better."

Whenever you are comparing only two things, use the comparative form (usually words ending in "-er"—better, smarter, faster, and so forth). If there are three or more items, use the superlative form (usually ending in "-est"—best, smartest, fastest . . .) to designate the best one.

We use comparative adjectives when comparing two people or things (bigger, worse); we use superlative adjectives when comparing one person or thing with three or more people or things (the biggest, the worse).

We use comparative adjectives when comparing two people or things (bigger, worse, etc.); we use superlative adjectives when comparing one person or thing with three or more people or things (the biggest, the worst, etc.). Thus, here we use the superlative adjective “the shortest.” In the first clause, we use “me” instead of “I” because “me” is an object pronoun, and “me” is the indirect object of the verb “look.”.

The use of the form "strongest" is a superlative that indicates the peak of an adjective; therefore, there can be only one "strongest boy," and the phrase needs a definite article, "the," instead of the indefinite article, "a."

"More well" is not a phrase—the comparative form of "well" is not "more well," but "better." Since we are only comparing two groups (the speaker versus the speaker's friends), "better" is the most appropriate here.

In the sentence as it is written, "fast," an adjective, is being used to modify "walks." This is incorrect; only adverbs can modify verbs. So, we need to pick out an answer choice which uses the adverbial form of "fast," which is "quickly." This lets us eliminate the answer choice "most fast." "Faster" cannot be correct because more than two subjects are being compared in the sentence, and "faster" is a comparative adjective that is used to compare two subjects. "More quick," "more fast," and "more quickly" can each be eliminated for this same reason, in addition to the fact that "more quick" isn't grammatically correct at all—one would say "quicker," not "more quick." This leaves us with the correct answer, "most quickly."

We must compare the chefs to my mother, not to the home-cooked meals.

The use of "more" in this sentence is odd and confusing, as "more" should be used in a direct comparison between two things. As no comparison is made in this sentence, the modifier should simply indicate a great degree of difficulty. The word "most," a superlative adjective, properly conveys such a meaning, making the correct answer, "The most difficult step in the process for all of the initiates was the lengthy obstacle course."