One of my faithful readers responded to last week’s call for grammar questions with this challenge: farther vs. further. That can be deceptively tough to answer.

Some sticky grammar problems lead me to the OED.

After consulting the Web and two of the trustiest dictionaries I could get my hands on (OED and Webster’s Third New International Dictionary), I’m not surprised this one stumps many of us.

Popular usage rules dictate that you would use farther for measurable distances and further for anything else. Notice I say popular usage rules. You see, as with many English grammar rules, further vs. farther is more—or possibly less—complicated than I realized.

Here are some examples of the correct way to use these two words in popular usage:

Barbara ran farther than she did yesterday, while Hope did not run far at all.

Further, Barbara runs every day, while Hope takes some days off.

Barbara’s running is further aided by good genes and no injuries.

I’ll note that as I type this post, WordPress’ spell checker has flagged farther in the example above.

Keep reading for more examples—complete with pretty pictures—and a brief tour of the rabbit hole I fell into when I cracked open my parents’ OED (the version that fits into two volumes of microscopic text and comes with its own magnifying glass.)

My crape myrtle is reaching farther than it did last year.

My lamb’s ear is growing farther, too. Of further delight to me, it looks a lot healthier than it did about a month ago.

Here’s what I discovered when I was reading the OED’s entries for farther and further today. For centuries further and farther have been interchangeable in most cases. They share a common etymology from Middle English ferþer. The entry for farther begins this way:

In standard Eng. the form farther is usually preferred where the word is intended to be the comparative of far, while further is used where the notion of far is altogether absent; there is a large intermediate class of instances in which the choice between the two forms is arbitrary.”

As I read, I could feel another red hair turning gray at this news. And I could empathize with my students’ reluctance to turn to the dictionary for answers. I mean, really: Arbitrary? Doesn’t that mean your guess is as good as mine?

My trusty Webster’s helped just about as much. Here’s how the first two entries for further appear:

If this keeps on, I’ll have to change these post titles to the former redhead’s red pen.

Here’s a little summary for you of the two words as defined in the OED, with the year of some of the OED’s earliest examples (Note the remarkable similarities between the adverb forms of both words):

farther

adv.
1. more forward
a) in space (1300)
b) in time
2. to a greater extent (1513)
3. in addition/also (1380)
4. to or at a greater distance (1380)

farther
v. (now rare) to help forward, promote, favor assist (1000–1390)

Additional words include fartherance, fartherer (one who farthers), farthermore and farthermost.

further
adj.
1. that is before another in position, order or rank (esp. an animal’s limbs), now obsolete.
2. more extended, going beyond what already exists, additional, more (1300)
3. more distant, remoter
4. further of the day, a later hour (1545)

further
adv.
1. to or at a more advanced point of progress (1000)
a) of space (1855)
b) of time (1390)
2. to a greater extent, more (1050)
3. In addition, additional, moreover
4. at a greater distance in space

further
v.
1. to help forward, assist, promote
2. to honor (obsolete/rare)
3. to advance, make progress
4. to defer, postpone (obsolete)

Additional words include furtherover, furtherous and furthersome (all of which activate both WordPress’ spell check and its autocorrect).

No wonder someone along the way decided to cut out the confusion by creating the hard and fast rule we (mostly) follow now: farther is for actual distances that go beyond far but not as far as farthest. Further is for anything else.

Good luck, and let me know if you have any other grammar questions you’d like me to cover in a future back-to-school post. (I wouldn’t mind a softball question next time.) And if you need a diversion from all this grammar, may I suggest visiting irunfar.com to read about amazing feats of running. And God bless them for not naming the site irunfarther.