I know this one, but while editing today, I had a brain freeze and had to refer to my cheat notes to choose which word was correct in my sentence:
The farther they travelled, the lower the ceiling became.
Was I right or wrong?
Farther and Further
The word farther implies a measurable distance.
I threw the ball ten feet farther than Ed.
Further should be reserved for abstract or hypothetical lengths.
The executive climbed further up the ladder of success.
