The king gathered together his people, and did not know whether or not he could offer any opposition to the enemy, who was superior in strength and had a mighty army.
— from Grimms' Fairy Tales by Wilhelm Grimm

To decline a noun of the third declension correctly we must know whether or not it is an i -stem.
— from Latin for Beginners by Benjamin L. (Benjamin Leonard) D'Ooge

“The fawning whelps of household curs will rise, And, shaking the soft slumber from their eyes, Oft bark and stare at ev’ry one within, As upon faces they had never seen.” to the beauty of the body, before I proceed any further I should know whether or no we are agreed about the description.
— from Essays of Michel de Montaigne — Complete by Michel de Montaigne

“The abrupt change in your behaviour to me I put down at first to coquetry,” Kirilin went on; “now I see that you don’t know how to behave with gentlemanly people.
— from The Duel and Other Stories by Anton Pavlovich Chekhov

In a way she still did not know whether or not she wanted him to come.
— from Winesburg, Ohio: A Group of Tales of Ohio Small Town Life by Sherwood Anderson

These then, though unbeheld in deep of night, Shine not in vain, nor think, though men were none, That heav’n would want spectators, God want praise; Millions of spiritual Creatures walk the Earth Unseen, both when we wake, and when we sleep: All these with ceasless praise his works behold Both day and night: how often from the steep Of echoing Hill or Thicket have we heard Celestial voices to the midnight air, Sole, or responsive each to others note Singing thir great Creator: oft in bands While they keep watch, or nightly rounding walk With Heav’nly touch of instrumental sounds In full harmonic number joind, thir songs Divide the night, and lift our thoughts to Heaven.
— from Paradise Lost by John Milton

Then he began: “I don't know whether or not you know what you—what I'm going to say.
— from This Side of Paradise by F. Scott (Francis Scott) Fitzgerald

Do you know whether or not he ever borrowed or used any wrapping paper for himself?
— from Warren Commission (06 of 26): Hearings Vol. VI (of 15) by United States. Warren Commission

Yet she could not refrain from turning up the hill, so anxious was she to know whether or not Miss Miranda had returned.
— from The Pool of Stars by Cornelia Meigs

It was not known whether or not the Orange & Alexandria railroad was still held by the Union troops.
— from Mosby's War Reminiscences; Stuart's Cavalry Campaigns by John Singleton Mosby

"I only want to know whether or not he will go with us."
— from The Yacht Club; or, The Young Boat-Builder by Oliver Optic

"But we're sure there's gold here," objected Jed, "and we don't know whether or not there's any further on."
— from Two Boy Gold Miners; Or, Lost in the Mountains by Frank V. Webster

A wonderful instinct, neither selfishness nor reason, perhaps the first innocent beginnings of sentiment teaches children to know whether or not they are the first and sole thought, to find out those who love to think of them and for them.
— from The Works of Balzac: A linked index to all Project Gutenberg editions by Honoré de Balzac

By the time he reached the foot of the hill Bancroft’s mind was once more engrossed with the need of knowing whether or not he was at last secure from ignominious exposure.
— from The Delafield Affair by Florence Finch Kelly

The loss of the north, i.e. the area north of the Yellow River and of parts of Kiangsu, was of no importance to this governing group and meant no loss of estates to it.
— from A History of China by Wolfram Eberhard

But sometimes it was quite difficult to know whether or not that was his primary assignment after all.
— from The Unlearned by Raymond F. Jones

I want you to know whether or not these routes were important, whether it was proper to carry the mails as they were carried, whether it was proper that they should be carried from once to seven times a week, and whether it was proper that the speed should be expedited.
— from The Works of Robert G. Ingersoll, Complete Contents Dresden Edition—Twelve Volumes by Robert Green Ingersoll