Indirect questions.
Or they may introduce indirect questions of—
(1) Time.
I do not remember when I was taught to read.—D. Webster.
(2) Place.
I will not ask where thou liest low.—Byron
(3) Manner.
Who set you to cast about what you should say to the select souls, or how to say anything to such?—Emerson.
(4) Degree.
Being too full of sleep to understand
How far the unknown transcends the what we know.
—Longfellow