Observe. The dictionaries authorize the use of this word as a synonym of say and remark; as, for example, "What did you observe?" for "What did you say, or remark?" In this sense, however, it is better to leave observe to the exclusive use of those who delight in being fine.
O'clock. "It is a quarter to ten o'clock." What does this statement mean, literally? We understand by it that it lacks a quarter of ten, i. e., of being ten; but it does not really mean that. Inasmuch as to means toward, it really means a quarter after nine. We should say, then, a quarter of, which means, literally, a quarter out of ten.
Of all others. "The vice of covetousness, of all others, enters deepest into the soul." This sentence says that covetousness is one of the other vices. A thing can not be another thing, nor can it be one of a number of other things. The sentence should be, "Of all the vices, covetousness enters deepest into the soul"; or, "The vice of covetousness, of all the vices, enters," etc.; or, "The vice of covetousness, above all others, enters," etc.
Of any. This phrase is often used when of all is meant; thus, "This is the largest of any I have seen." Should be, "the largest of all," etc.
Off of. In such sentences as, "Give me a yard off of this piece of calico," either the off or the of is vulgarly superfluous. The sentence would be correct with either one, but not with both of them. "The apples fell off of the tree": read, "fell off the tree."
Often. This adverb is properly compared by changing its termination: often, oftener, oftenest. Why some writers use more and most to compare it, it is not easy to see; this mode of comparing it is certainly not euphonious.
Oh—O. It is only the most careful writers who use these two interjections with proper discrimination. The distinction between them is said to be modern. Oh is simply an exclamation, and should always be followed by some mark of punctuation, usually by an exclamation point. "Oh! you are come at last." "Oh, help him, you sweet heavens!" "Oh, woe is me!" "Oh! I die, Horatio." O, in addition to being an exclamation, denotes a calling to or adjuration; thus, "Hear, O heavens, and give ear, O earth!" "O grave, where is thy victory?" "O heavenly powers, restore him!" "O shame! where is thy blush?"
Older—Elder. "He is the older man of the two, and the oldest in the neighborhood." "He is the elder of the two sons, and the eldest of the family." "The elder son is heir to the estate; he is older than his brother by ten years."
On to. We get on a chair, on an omnibus, on a stump, and on a spree, and not on to.
One. Certain pronouns of demonstrative signification are called indefinite because they refer to no particular subject. This is one of them. If we were putting a supposition by way of argument or illustration, we might say, "Suppose I were to lose my way in a wood"; or, "Suppose you were to lose your way in a wood"; or, "Suppose one were to lose one's way in a wood." All these forms are used, but, as a rule, the last is to be preferred. The first verges on egotism, and the second makes free with another's person, whereas the third is indifferent. "If one's honesty were impeached, what should one do?" is more courtly than to take either one's self or the person addressed for the example.