Where to use "only" in a sentence is a moot question, one of the mootest questions in all rhetoric. The purist will say that the expression: "He only died last week," is incorrect, and that it should be: "He died only last week." The purist's contention is that the first sentence, if carried out to a natural conclusion, would give us something like this: "He only died last week, he didn't do anything else, that's all he did." It isn't a natural conclusion, however, because nobody would say that and if anybody did it would be likely to lead to stomping of feet and clapping of hands, because it is one of the singy-songy expressions which set a certain type of person to acting rowdy and becoming unmanageable. It is better just to let the expression go, either one way or the other, because, after all, this particular sentence is of no importance except in cases where one is breaking the news to a mother. In such cases one should begin with: "Mrs Gormley, your son has had an accident," or: "Mrs. Gormley, your son is not so good," and then lead up gently to: "He died only last week."
The best way is often to omit "only" and use some other expression. Thus, instead of saying, "He only died last week," one could say: "It was no longer ago than last Thursday that George L. Wodolgiffing became an angel." Moreover, this is more explicit and eliminates the possibility of a misunderstanding as to who died. The greatest care in this regard, by the way, should be taken with the verbs "to die," "to love," "to embezzle," and the like. In this connection, it is well never to use "only" at the beginning of a sentence - "Only one person loves me," for example. This of course makes it necessary to capitalize "Only" and there is the risk of a hurried reader taking it for a proper noun and confusing it with the late Richard Olney, who was Secretary of State under Cleveland.
The indefinite "one" is another source of trouble and is frequently the cause of disagreeable scenes. Such a sentence as "One loves one's friends" is considered by some persons to be stilted and over-formalized, and such persons insist that "One loves his friends" is permissible. It is not permissible, however, because "one" is indefinite and "his" is definite and the combination is rhetorically impossible. This is known as hendiadys and was a common thing in Latin. Rare examples of it still exist and are extremely valuable as antiques, although it is usually unsafe to sit or lie down on one.
The chief objection to a consistent, or "cross-country" use of "one" is that it tends to make a sentence sound like a trombone solo - such as: "One knows one's friends will help one if one is in trouble, or at least one trusts one's friends will help one." Even though this is correct, to the point of being impeccable, there is no excuse for it. The "one" enthusiast should actually take up the trombone and let it go at that.
"One" is, as a matter of fact, too often used for the personal pronoun. What, for example, could be sillier than to write a lady like this: "One loves you and one wonders if you love one." Such a person is going to get nowhere. "I love you. Do you love me?" is a much simpler and better way to say it, except of course, that there is always the danger here of drifting into a popular ballad of the "Ramona" type.
Some persons use neither the indefinite "one" nor the definite pronoun, but substitute a pet name and get some such result as "Mopsy loves Flopsy and wonders if Flopsy loves Mopsy." This usage frequently gets into the newspapers and becomes famous, particularly if Flopsy is an ambitious blonde and Mopsy a wealthy mop-handle manufacturer. The fault here, however, is not so much with the nouns of pronouns as with the verb, "to love." Nothing can be done about the verb "to love."
Ladies' and Gentlemen's Guide to Modern English Usage