Run farther up the road to the library; there, you can further your knowledge.
Further [THINK: figurative (U)]
Farther [THINK: physical distance (A)]
“Do you use farther and further interchangeably? You’re not alone….”
FARTHER:
“The widely accepted rule is to use farther to discuss physical distances, as in He went farther down the road.”
FURTHER:
“Further should be used for figurative distance or to discuss degree or extent….or advance, a project…. Further also has an adverbial sense of “moreover; additionally…”
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