Chapter 9-4-2: The Interrogative Sentence
An interrogative sentence asks a direct question and always ends in a question mark:
Who can read this and not be moved?
How many roads must a man walk down?
Does money grow on trees?
Note that an indirect question does not make a sentence interrogative:
When was Lester Pearson prime minister?
I wonder when Lester Pearson was prime minister.
A direct question requires an answer from the reader, while an indirect question does not.