When should "farther" and "further" be used?

I know I learned the difference between the usage of farther and further in school, but I can never remember where each one should be used. Can someone help me out here?

Solution 1:

English originally had "further" as the comparative form of "fore" and "farrer" as the comparative of "far." "Farther" came later, presumably as a back-formation, and has been interchangeable with "further" throughout most of the history of the written language. The differentiation between "further" and "farther" seems to have been invented ca. 1900 by grammarians. It's not a distinction that has ever been widely accepted, and it's not worth fighting to maintain it because it doesn't enrich the language. Because it has never been a natural part of the language, there is not widespread agreement on what criterion should be used to distinguish them: figurative versus literal, or addition versus distance. There is no clear evidence that the best writers have systematically observed the distinction. "Further" can be used literally:

She said the morning was so beautiful that she had walked further than she intended [...] -- Dickens, Martin Chuzzlewit, 1844

"Farther" can be used figuratively:

If you can bear your load no farther, say so. Is it manly to bring new sufferings on us all by irritating those whom we cannot resist? -- H. Martineau, The Charmed Sea, 1834

To many people's ears, including mine, the figurative use of "farther" sometimes sounds a little off ("I could use some farther income."), but that doesn't mean it's incorrect. Literal "further" may be more common in British English than in American English.

There is no value in trying to fight for the distinction, since it doesn't help us to make shades of meaning; the meaning is either literal or figurative based on the context, and this distinction can't be blurred or confused by which form of the word we choose.

Even relative prescriptivists such as Fowler (Fowler's Modern English Usage, 2e) don't advocate for maintaining the difference between the words, and the OED doesn't find much historical support for it.

The following points may be helpful for nonnative speakers:

• There is a transitive verb "further," but no transitive verb "farther." There are related forms like "furthering" and "furtherance," but no such forms based on "farther."
• We have "furthermore" but not "farthermore."
• The usage that is most likely to sound wrong to 21st-century speakers is "farther" in the figurative sense.

For all of these reasons, nonnative speakers are safer saying "further" when in doubt. Substituting "further" for "farther" is never incorrect, and many native speakers use "further" exclusively. Fowler speculates that "further" is eventually going to displace "farther" completely.

Solution 2:

Farther is used for distance. Further is used for all other purposes.

Examples:

• I ran farther than he did.
• After giving him the gift, I wished to further express my gratitude by hugging him.

Solution 3:

"Further' versus 'farther' in the sense of distance

It is rather difficult to obtain uncompromised comparisons of the frequency of use of further and farther in the sense of distance because any head-to-head comparison includes many instances of further in situations where the intended meaning is "in addition" or "more deeply"—meanings that few people today are inclined to use farther to signify.

To get a sense of the trends in usage of further and farther in the sense of distance, I generated two Ngram charts. The first matches "further than" (blue line) against "farther than" (red line) over the period 1750–2005:

This chart shows a fairly steady advantage for "further than" over "farther than" from a surprisingly early date (1840). However, there are still instances of "further than" that do not refer even figuratively to distance, such as in this match from Arthur Collins, Peerage of England (1756):

Which thing considered, they thought it better to return without doing their commission, and declare this much to their Lordships, without meddling any further, than to proceed in the execution of their charge be fore they had advertised their Lordships of the premisses.

and many others that use further in at most a figurative sense based on distance, as in this example, from Andrew Jackson, "Message of the President of the United States to Both Houses of Congress" (December 4, 1832), reprinted in Register of Debates in Congress (1833):

Further than this, it is neither our policy nor our right to interfere. Our best wishes on all occasions, our good offices when required, will be afforded, to pro- mute the domestic tranquillity and foreign peace of all nations with whom we have any intercourse. Any intervention in their affairs further than this, even by the expression of an official opinion, is contrary to our principles of international policy, and will always be avoided.

Still there are many matches for further in which distance is the intended meaning of the word. For example, from William Hone, The Every-day Book and Table Book; Or, Everlasting Calendar of Popular Amusements (1838):

After passing in a north by east direction about a mile and a half further than Mr. Bellas's farm, its [the storm's] fury most probably subsided, as the only further mischief I have been able to trace was the destruction of two small elms in a hedgerow, and whose support had been weakened by digging away the earth from their roots.

Here the first further refers to "distance away from" and the second further means "additional."

For a better one-to-one comparison with regard to the sense of "distance," I offer this chart (again for the period 1750–2005) tracking furthest (blue line) against farthest (red line):

This chart shows a significant preference for farthest over furthest. The advantage in frequency that farthest enjoyed in the first half of the 1900s dropped rather sharply between 1940 and 1980, but it appears to have leveled off for the period from 1980 to 2005.

Still, the main point to be gleaned from this second chart is that furthest has for the past two and a half centuries appeared regularly in published writing as an alternative to farthest in the sense of distance. Any rule insisting that further is improper as applied to distance must concede that actual practice has flouted that rule for centuries.

The emergence of the 'further'/'farther' distinction in usage guides

For the most part, early nineteenth-century grammars do not endorse (or even acknowledge) the rule that farther applies to distances and further to "everything else." Seth Hurd, A Grammatical Corrector; Or, a Vocabulary of the Common Errors of Speech (1847), for example, doesn't mention farther at all; but in the context of a chart of correct and incorrect pronunciations, he includes this example:

FURTHER . They could travel no . .

And Alexander Bain, English Composition and Rhetoric: A Manual (1867) uses further and farther seemingly interchangeably, including in such rule-breaking contexts as

Let us consider some farther examples of the foregoing principles.

and

The Alps consist, in their eastern portion, of several parallel ranges, running in a general east and west direction ; westward of the 9th meridian, these are diminished to two chains, divided by the valley of the river Rhone ; and still further to the west, where they bend southward, they form a single chain, or axis of elevation, though with numerous offsets, which occupy the country on either side.

Nevertheless, several usage commentators from the middle of the nineteenth century do argue that further and farther properly apply to different spheres.

From Peter Bullions, The Principles of English Grammar: Comprising the Substance of the Most Approved English Grammars Extant (1843):

Farther and Farthest,—Further and Furthest.

Farther and farthest denote place or distance : Further and furthest, quantity or addition ; as, "The farther they advanced, the more interesting was the scene." "I have nothing further to say on this subject." Farther is the comparative, and farthest, the superlative, of far ; Further and furthest, of fore or forth.

From George Graham & Henry Reed, English Synonymes Classified and Explained: With Practical Exercises (1847):

Further—Farther.

The positive degree of the first of these words is forth, which is compared thus : — forth ; further ; furthest. The second word is compared thus : far ; farther ; farthest. Further, then, means more in advance ; farther, at a greater distance. When we are further on out journey, we are farther from the starting place. In abstract language, the same distinction should be maintained. One boy may be much further (in his studies) than another. After many trials, we may be farther than ever from success.

From Rufus Bailey, English Grammar: A Simple Concise and Comprehensive Manual of the English Language (1855):

Farther relates to place — from far — farther, farthest.

Further relates to addition — from forth — further, furthest.

Admittedly, these early authorities by no means fully agree as to the particular distinctions that the words farther and further imply. But they do insist that the meanings are different and that the distinction that they fancy they see should be zealously enforced. It follows that a key assertion in the accepted answer above ("The differentiation between 'further' and 'farther' seems to have been invented ca. 1900 by grammarians") is off by at least half a century—if indeed it is accurate to say that those grammarians of the 1840s and 1850s invented the distinction out of whole cloth, rather than that they may have detected some degree of difference in the way that English speakers of their time actually tended to use the two words, and sought to raise that tendency to a rule of usage.