Which sentence contains an error in its verb? A. Either footnotes or endnotes are acceptable. B. Neither bananas nor squash was for sale. C. Both Clara and Nathan is planning to attend. D. Not only the players but also coach Jarvis was late for practice.
I believe answer "c" contains the error. Instead of the verb "is," it should be the verb "are" because if you were to replace "Both Clara and Nathan" with the plural pronoun "they," the verb "are" would make the most sense.