In this sentence, the plural verb “are” does not agree with its singular subject “variation.” The corrected sentence reads, "The variation between seasons is caused by the tilt of the planet; summer happens where sunlight is hitting the earth more directly."

The subject of this sentence is “the president,” which is singular. The other members of the board are just added information. The verb “make” should agree with a singular subject. The corrected sentence reads: "The president of the college, along with other members of the board, makes decisions regarding the college's finances, its mission, and its education policy."

In this sentence, the verb “require” should agree in number with its subject “creation.” Here, it incorrectly agrees with “flavors.” The corrected sentence reads, "Cooking is not often considered a fine art, but the creation of delicious meals that balance flavors requires a real sense of artistry."

This sentence has a problem with subject-verb agreement. The subject “trees” is plural, but the verb “is” is singular. The corrected sentence reads: "The ash trees that line the long driveway up to the mansion are diseased and likely to die soon."

In this sentence, the verb “is preparing” does not match its plural subject “agencies.” The corrected sentence reads, "The agencies collaborating on the investigation are preparing a joint statement to share their findings with the press."

The verb “signifies” should match in number with the compound subject, “purple glitter and a mysterious odor.” For a plural subject, “signify” would be correct. The corrected sentence reads, "Purple glitter and a mysterious odor often signify the presence of Peruvian Sea Slugs, animals that are both rare and beautiful."

The subject of this sentence is compound and plural, but the verb agrees with a singular subject. The corrected sentence reads, "The glaring sun, the intense music, and the actor's solemn speech combine to form an overdramatic effect."

In this sentence, the main verb "are" agrees with a plural subject. However, its subject is singular: "the accusation." The corrected sentence reads, "The accusation that the new neighbors stole my family's container gardens is a blatant lie."

The verb “were” agrees with a plural noun, but here its subject is the singular noun “railroad.” The corrected sentence reads, "The railroad between the towns of Greensburg and Rodbury was destroyed in the alien invasion last week."

The subject “The rich and the famous” refers to many people, and should be treated as a plural subject. However, the verb “eats” agrees with a singular subject. The corrected sentence would read, "The rich and the famous often eat in the fancy restaurants on Main Street."