The indefinite adjective pronoun _one_ when put in place of a personal
substantive is liable to raise confusion. When a sentence or expression
is begun with the impersonal _one_ the word must be used throughout in
all references to the subject. Thus, "One must mind one's own business if
one wishes to succeed" may seem prolix and awkward, nevertheless it is
the proper form. You must not say--"One must mind his business if he
wishes to succeed," for the subject is impersonal and therefore cannot
exclusively take the masculine pronoun. With _any one_ it is different.
You may say--"If any one sins he should acknowledge it; let him not try
to hide it by another sin."


ONLY

This is a word that is a pitfall to the most of us whether learned or
unlearned. Probably it is the most indiscriminately used word in the
language. From the different positions it is made to occupy in a sentence
it can relatively change the meaning. For instance in the sentence--"I
_only_ struck him that time," the meaning to be inferred is, that the
only thing I did to him was to _strike_ him, not kick or otherwise abuse
him. But if the _only_ is shifted, so as to make the sentence read-"I
struck him _only_ that time" the meaning conveyed is, that only on that
occasion and at no other time did I strike him. If another shift is made
to-"I struck _only_ him that time," the meaning is again altered so that
it signifies he was the only person I struck.

In speaking we can by emphasis impress our meaning on our hearers, but in
writing we have nothing to depend upon but the position of the word in
the sentence. The best rule in regard to _only_ is to place it
_immediately before_ the word or phrase it modifies or limits.