Fail. "He failed to note the hour." That implies that he tried to note it, but did not succeed. Failure carries always the sense of endeavor; when there has been no endeavor there is no failure. A falling stone cannot fail to strike you, for it does not try; but a marksman firing at you may fail to hit you; and I hope he always will.
Favor for Resemble. "The child favors its father."
Feel of for Feel. "The doctor felt of the patient's head." "Smell of" and "taste of" are incorrect too.
Feminine for Female. "A feminine member of the club." Feminine refers, not to sex proper, but to gender, which may be defined as the sex of words. The same is true of masculine.
Fetch for Bring. Fetching includes, not only bringing, but going to get--going for and returning with. You may bring what you did not go for.
Finances for Wealth, or Pecuniary Resources.
Financial for Pecuniary. "His financial reward"; "he is financially responsible," and so forth.
Firstly. If this word could mean anything it would mean firstlike, whatever that might mean. The ordinal numbers should have no adverbial form: "firstly," "secondly," and the rest are words without meaning.
Fix. This is, in America, a word-of-all-work, most frequently meaning repair, or prepare. Do not so use it.
Forebears for Ancestors. The word is sometimes spelled forbears, a worse spelling than the other, but not much. If used at all it should be spelled forebeers, for it means those who have been before. A forebe-er is one who fore-was. Considered in any way, it is a senseless word.
Forecasted. For this abominable word we are indebted to the weather bureau--at least it was not sent upon us until that affliction was with us. Let us hope that it may some day be losted from the language.
Former and Latter. Indicating the first and the second of things previously named, these words are unobjectionable if not too far removed from the names that they stand for. If they are they confuse, for the reader has to look back to the names. Use them sparingly.
Funeral Obsequies. Tautological. Say, obsequies; the word is now used in none but a funereal sense.
Fully for Definitively, or Finally. "After many preliminary examinations he was fully committed for trial." The adverb is meaningless: a defendant is never partly committed for trial. This is a solecism to which lawyers are addicted. And sometimes they have been heard to say "fullied."
Funds for Money. "He was out of funds." Funds are not money in general, but sums of money or credit available for particular purposes.
Furnish for Provide, or Supply. "Taxation furnished the money." A pauper may furnish a house if some one will provide the furniture, or the money to buy it. "His flight furnishes a presumption of guilt." It supplies it.