I might not be terribly appreciated where I work, but I am pretty sure I could make something of myself in a government set up. The reason I am saying this is, I got a letter from a government agency telling me that they are going to get in touch with me to discuss the issue “farther”.
You know, if I had my way, I’d probably give a slap on the wrist of whoever wrote that letter to me and tell him/her the difference between “further” and “farther”. Oft-confused, yes, but also very easy to straighten it out. “Farther” is used when you are talking about a physical distance (note the word “far” in “farther”). So if I were tired of walking for hours and not finding that red flag you told me to find, I’d probably ask you, “How much farther is it?”
“Further” on the other hand, refers to a metaphorical or figurative distance.So if you kept telling me that I am nearly where you put the red flag and I knew that wasn’t true, I’d tell you, “If you lie any further about it, I’ll punch you.” Easy? Recap: Only when you are talking about a measurable physical distance will you use “farther” and when you are talking about a figurative distance, you will use “further”. So you travel “farther” or you place the can of pickles farther up on the shelf but you discuss the matter further, and you do not humour the spoilt brat any further.
Sometimes though it becomes difficult to choose one of the words. Say you were reading a book and you put it down saying you can’t read any more of it. So do you say “I can’t read any further” or “I can’t read any farther”. Both are correct, because in the first instance you mean you cannot read through the story (figurative distance in the book) and in the second, you mean you can’t read any more pages (physical distance in the book).
There may also be confusion when you are interrupting someone to make point. do you say “Let’s stop before we discuss this any further” or do you say “…before we discuss this any farther”? Both may be correct. Worry not, because the Oxford English Dictionary, Fowler’s Modern English Usage, and a number of other sources say that, in most cases, it’s fine to use “further” and “farther” interchangeably, especially when the distinction isn’t clear.
I cannot think of any thing to say any further, so I shall not extend this post two lines farther.