Farther vs. further
Farther and further both mean at a greater distance, and they are used interchangeably in this sense. In the United States, though, farther is more often used to refer to physical distances, and further more often refers to figurative and nonphysical distances. For example, we might say that one mountain is farther away than another, while we might say the price of a stock (a nonphysical thing) fell further today than yesterday. This is not a rule, however, and further is often used for physical distances. The distinction does not exist in the U.K. and elsewhere in the (British) Commonwealth of Nations, where further is preferred for all senses of the word and farther is rare.
Further has senses it does not share with farther. It works as an adjective meaning additional—e.g., “I have no further questions.” It works as an adverb meaning additionally—e.g., “He said he did not spend the money, and stated further that he had never even received it.” And it works as a verb meaning to advance (something)—e.g., “This website is meant to further understanding of 21st-century English.” Farther is not commonly used these ways.
The physical/nonphysical distinction in the U.S. extends to the superlatives farthest and furthest. Furthermore is an adverbial extension of further and often bears replacement with the shorter word. The rare furthermost is sometimes used to mean farthest or furthest, and it likewise bears replacement with the shorter words.
Some more . . .
Farther vs. Further
by Mark Nichol
Is there any difference between farther and further?
Merriam-Webster’s online dictionary notes in a usage discussion that as an adverb, farther and further are used indiscriminately when literal or figurative distance is involved:
“How much farther do we have to go?”
“It’s just a mile further.”
“How much further do you want to take this argument?”
“I’ve taken it farther than I want to already.”
However, in adjectival form, a distinction has developed regarding use in these senses:
“My house is the farther of the two.”
“She needs no further introduction.”
But dictionaries are descriptive; they describe not how people should use language, but how they do use it. However, language maven (and therefore prescriptive) Bryan A. Garner, in Garner’s Modern English Usage, advises, “In the best usage, farther refers to physical distances, further to figurative distances,” and I agree: Popular usage demonstrates just that — popular usage — and the careful writer maintains distinctions that enrich the language. (Write eager when you mean eager, for example, and anxious when you meananxious.)
Farthest and furthest, by extension, should maintain the same distinct meanings; use these forms in favor of the burdensome farthermost andfurthermost. Furthering and furtherance are interchangeable noun forms that serve as synonyms for promotion or advocacy; there is no equivalent noun form for farther.
Further is also employed as a modifier, as in “Further, I see no reason to delay the proceedings”; furthermore is a variant. Farther, however, does not fit this role.
This Daily Writing Tips post from a former contributor has a somewhat different take; as always, consider what you read here (and there) a springboard (or two) for farther — I mean further — research to help you make up your mind about how you write.