Answer:
If I were an American citizen listening to FDR’s speech, it would have affected me in a strong way. I would have felt a sense of horror at the surprise attack by the Japanese and a sense of indignation that they would have dared to attack us on our own home soil.
A singular verb would be used with a singular noun (she, Bob, Jane, truck) while a plural verb would be used with a plural noun (they, cars, books).
For example "The truck drives away." Truck being a singular noun and drives being a singular verb.
Another example
"The cars drive away." cars being a plural noun and drive being the plural verb.