Don't be confused here by the plural nouns "trails" and "parks"—neither of these is the subject of the sentence's main clause; they merely add information about the subject. "Running," may initially seem to be a verb, but here it is functioning as a gerund, a verbal ending in "-ing" that functions as a noun. As such, it is a singular subject and needs to take the singular verb "is," making "are" incorrect.

The verb "does" is used with singular nouns, but in the sentence as it is written, it refers to "types," a plural noun. To correct the sentence's error, we would need to change "does" to "do," or omit "do" completely, as just the "than" is sufficient to make the comparison.

This sentence is about two families (plural) that are successful. The sentence has them becoming the leader (singular) in the region. This discrepancy in number is an error. The corrected sentence reads: The two families developed their farms in friendly competition and eventually became the leaders of the region’s dairy production.

This sentence lacks agreement between subject and verb. “Is” corresponds with a singular subject, but here the subject is plural. The corrected sentence reads: Unfamiliar customs and a sharp intelligence are intimidating, but a good sense of humor is very disarming.

The problem with this sentence is that the verb “makes” does not agree with the plural subject “colors and . . . patterns.” The corrected sentence reads, "The vibrant colors and unique patterns that decorate the doorway make the house stand out from the rest of the suburban clones."

People get these kinds of questions wrong because of the phrase set apart from the rest of the sentence by commas. That little seperation between the first and second part of the sentence is a distraction to subject-verb agreement. When read quickly, it may seem like "paint," which is singular, is the subject. The real subject, however, is "cans." This means our verb has to agree with a plural noun, and so "was" contains the error, because "was" should be "were."

This question tries to confuse you by putting "shoes" after "closet." "Are" should be "is" as "closet" is the subject of the verb.

The predicate of this sentence does not match in number with the single subject “trail.” The corrected sentence reads: The trail of ants, which crossed the entire kitchen floor and disappeared into the cabinet, was a new arrival this morning.

In this sentence, the verb does not agree with the number of the subject. The subject is singular (the administrative staff is in a modifying phrase and doesn’t count), so the correct verb form would be “is.” The corrected sentence reads, "The events director, along with the administrative staff, is responsible for making sure the entire program runs smoothly."

In this sentence, the verb does not agree with the subject. “Were” should go with a plural subject, but here the subject “the sloth” is singular. The corrected sentence reads, "The sloth, out of all the zoo animals, was what fascinated Peter the most."