Further/Farther

Further

Used for time or quantity, not distance (46). E.g. I pursued Spanish further than any of my colleagues because I wanted to become the new regional sales manager for Latin America.

Farther

Used for distance. E.g. They ran farther down the hill to check if the others were catching up.

Quiz

Source:

Strunk, William, and E.B. White. The Elements of Style. Fourth Edition. Massachusetts: Allyn & Bacon, 2000. Print.