Although they are often used interchangeably, "further" and "farther" don't have exactly the same meaning. Basically, "farther" refers to actual distances between objects while further refers to figurative distances or something that is additional or more. Here are some easy-to-understand definitions and examples of how to use the two words.
Farther refers to a greater physical distance, a distance that has been measured.
When used as an adjective, "farther" describes when one object is more distant than the other, requiring a measurement of the distance from one common point to both objects.
When used as an adverb, "farther" indicates an action that results in a greater distance.
Further is defined as something that is additional or more, as well as referring to distance. It is used when there is no knowledge of the actual physical or time difference.
When used as an adverb, "further" expresses a relationship to a place or time, something additional or to a greater degree.
When used as an adjective, "further" describes a distance or something that is beyond or additional. It can also refer to something that is greater in degree or amount.
When functioning as a verb, "further" refers to an action of helping something move forward, usually in a symbolic rather than a literal sense.
One of our YourDictionary readers shared a great way to help you use "further" and "farther" correctly:
"If you can't replace "further" with "additional" or "more" in a sentence, you are probably using it incorrectly."
So, remember, you need to measure to use "farther," but you can use "further" in almost all other situations. However, if there is some confusion between it being a physical or figurative distance, it is now considered fine to use either word.
Ready to tackle some other potentially challenging word pairs? Learn the difference between affect and effect. Or do you understand the difference between an abbreviation and an acronym? Study up and you'll further your command of the English language.