FARTHER/FURTHER

It is not uncommon for people to be uncertain when choosing between farther and further. The latter is usually appropriate when relating to distance in a metaphorical way, and it may mean “moreover” in some contexts. One absolute difference is that “farther” is never used as a verb.

We run ever farther to further our joy,
Proceeding most strongly and, further, with verve.
We further the skeptics or maybe alloy,
But all will be certain that farther's no verb.

Remember that “further” is broader in scope,
​Beyond simple distance through space or in time.
When “far” is compared by extent or degree,
Then “further” beats farther, its reach more sublime.